generate_file() - Code Metrics - Inspection of "Add skip-if-file-exists when doing overwrite-if-ex..." - audreyr/cookiecutter - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#1076)

unknown

created 2018-05-28 16:04 UTC

generate_file() C

↳ Parent: Project

Complexity

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Metric	Value
cc	7
c	0
b	0
f	0
dl	0
loc	68
rs	5.8089

How to fix Long Method

# -*- coding: utf-8 -*-

"""Functions for generating a project from a project template."""
from __future__ import unicode_literals

import fnmatch
import io
import json
import logging
import os
import shutil
from collections import OrderedDict

from binaryornot.check import is_binary
from jinja2 import FileSystemLoader
from jinja2.exceptions import TemplateSyntaxError, UndefinedError

from .environment import StrictEnvironment
from .exceptions import (
    NonTemplatedInputDirException,
    ContextDecodingException,
    FailedHookException,
    OutputDirExistsException,
    UndefinedVariableInTemplate
)
from .find import find_template
from .hooks import run_hook
from .utils import make_sure_path_exists, work_in, rmtree

logger = logging.getLogger(__name__)


def is_copy_only_path(path, context):
    """Check whether the given `path` should only be copied and not rendered.

    Returns True if `path` matches a pattern in the given `context` dict,
    otherwise False.

    :param path: A file-system path referring to a file or dir that
        should be rendered or just copied.
    :param context: cookiecutter context.
    """
    try:
        for dont_render in context['cookiecutter']['_copy_without_render']:
            if fnmatch.fnmatch(path, dont_render):
                return True
    except KeyError:
        return False

    return False


def apply_overwrites_to_context(context, overwrite_context):
    """Modify the given context in place based on the overwrite_context."""
    for variable, overwrite in overwrite_context.items():
        if variable not in context:
            # Do not include variables which are not used in the template
            continue

        context_value = context[variable]

        if isinstance(context_value, list):
            # We are dealing with a choice variable
            if overwrite in context_value:
                # This overwrite is actually valid for the given context
                # Let's set it as default (by definition first item in list)
                # see ``cookiecutter.prompt.prompt_choice_for_config``
                context_value.remove(overwrite)
                context_value.insert(0, overwrite)
        else:
            # Simply overwrite the value for this variable
            context[variable] = overwrite


def generate_context(context_file='cookiecutter.json', default_context=None,
                     extra_context=None):
    """Generate the context for a Cookiecutter project template.

    Loads the JSON file as a Python object, with key being the JSON filename.

    :param context_file: JSON file containing key/value pairs for populating
        the cookiecutter's variables.
    :param default_context: Dictionary containing config to take into account.
    :param extra_context: Dictionary containing configuration overrides
    """
    context = {}

    try:
        with open(context_file) as file_handle:
            obj = json.load(file_handle, object_pairs_hook=OrderedDict)
    except ValueError as e:
        # JSON decoding error.  Let's throw a new exception that is more
        # friendly for the developer or user.
        full_fpath = os.path.abspath(context_file)
        json_exc_message = str(e)
        our_exc_message = (
            'JSON decoding error while loading "{0}".  Decoding'
            ' error details: "{1}"'.format(full_fpath, json_exc_message))
        raise ContextDecodingException(our_exc_message)

    # Add the Python object to the context dictionary
    file_name = os.path.split(context_file)[1]
    file_stem = file_name.split('.')[0]
    context[file_stem] = obj

    # Overwrite context variable defaults with the default context from the
    # user's global config, if available
    if default_context:
        apply_overwrites_to_context(obj, default_context)
    if extra_context:
        apply_overwrites_to_context(obj, extra_context)

    logger.debug('Context generated is {}'.format(context))
    return context


def generate_file(project_dir, infile, context, env, skip_if_file_exists=False):
    """Render filename of infile as name of outfile, handle infile correctly.

    Dealing with infile appropriately:

        a. If infile is a binary file, copy it over without rendering.
        b. If infile is a text file, render its contents and write the
           rendered infile to outfile.

    Precondition:

        When calling `generate_file()`, the root template dir must be the
        current working directory. Using `utils.work_in()` is the recommended
        way to perform this directory change.

    :param project_dir: Absolute path to the resulting generated project.
    :param infile: Input file to generate the file from. Relative to the root
        template dir.
    :param context: Dict for populating the cookiecutter's variables.
    :param env: Jinja2 template execution environment.
    """
    logger.debug('Processing file {}'.format(infile))

    # Render the path to the output file (not including the root project dir)
    outfile_tmpl = env.from_string(infile)

    outfile = os.path.join(project_dir, outfile_tmpl.render(**context))
    file_name_is_empty = os.path.isdir(outfile)
    if file_name_is_empty:
        logger.debug('The resulting file name is empty: {0}'.format(outfile))
        return

    if skip_if_file_exists and os.path.exists(outfile):
        logger.debug('The resulting file already exists: {0}'.format(outfile))
        return

    logger.debug('Created file at {0}'.format(outfile))

    # Just copy over binary files. Don't render.
    logger.debug("Check {} to see if it's a binary".format(infile))
    if is_binary(infile):
        logger.debug(
            'Copying binary {} to {} without rendering'
            ''.format(infile, outfile)
        )
        shutil.copyfile(infile, outfile)
    else:
        # Force fwd slashes on Windows for get_template
        # This is a by-design Jinja issue
        infile_fwd_slashes = infile.replace(os.path.sep, '/')

        # Render the file
        try:
            tmpl = env.get_template(infile_fwd_slashes)
        except TemplateSyntaxError as exception:
            # Disable translated so that printed exception contains verbose
            # information about syntax error location
            exception.translated = False
            raise
        rendered_file = tmpl.render(**context)

        logger.debug('Writing contents to file {}'.format(outfile))

        with io.open(outfile, 'w', encoding='utf-8') as fh:
            fh.write(rendered_file)

    # Apply file permissions to output file
    shutil.copymode(infile, outfile)


def render_and_create_dir(dirname, context, output_dir, environment,
                          overwrite_if_exists=False, skip_if_file_exists=False):
    """Render name of a directory, create the directory, return its path."""
    name_tmpl = environment.from_string(dirname)
    rendered_dirname = name_tmpl.render(**context)

    dir_to_create = os.path.normpath(
        os.path.join(output_dir, rendered_dirname)
    )

    logger.debug('Rendered dir {} must exist in output_dir {}'.format(
        dir_to_create,
        output_dir
    ))

    output_dir_exists = os.path.exists(dir_to_create)

    if output_dir_exists:
        if overwrite_if_exists:
            logger.debug(
                'Output directory {} already exists,'
                'overwriting it'.format(dir_to_create)
            )
        else:
            msg = 'Error: "{}" directory already exists'.format(dir_to_create)
            raise OutputDirExistsException(msg)
    else:
        make_sure_path_exists(dir_to_create)

    return dir_to_create, not output_dir_exists


def ensure_dir_is_templated(dirname):
    """Ensure that dirname is a templated directory name."""
    if '{{' in dirname and '}}' in dirname:
        return True
    else:
        raise NonTemplatedInputDirException


def _run_hook_from_repo_dir(repo_dir, hook_name, project_dir, context,
                            delete_project_on_failure):
    """Run hook from repo directory, clean project directory if hook fails.

    :param repo_dir: Project template input directory.
    :param hook_name: The hook to execute.
    :param project_dir: The directory to execute the script from.
    :param context: Cookiecutter project context.
    :param delete_project_on_failure: Delete the project directory on hook
        failure?
    """
    with work_in(repo_dir):
        try:
            run_hook(hook_name, project_dir, context)
        except FailedHookException:
            if delete_project_on_failure:
                rmtree(project_dir)
            logger.error(
                "Stopping generation because {} hook "
                "script didn't exit successfully".format(hook_name)
            )
            raise


def generate_files(repo_dir, context=None, output_dir='.',
                   overwrite_if_exists=False, skip_if_file_exists=False):
    """Render the templates and saves them to files.

    :param repo_dir: Project template input directory.
    :param context: Dict for populating the template's variables.
    :param output_dir: Where to output the generated project dir into.
    :param overwrite_if_exists: Overwrite the contents of the output directory
        if it exists.
    """
    template_dir = find_template(repo_dir)
    logger.debug('Generating project from {}...'.format(template_dir))
    context = context or {}

    unrendered_dir = os.path.split(template_dir)[1]
    ensure_dir_is_templated(unrendered_dir)
    env = StrictEnvironment(
        context=context,
        keep_trailing_newline=True,
    )
    try:
        project_dir, output_directory_created = render_and_create_dir(
            unrendered_dir,
            context,
            output_dir,
            env,
            overwrite_if_exists,
            skip_if_file_exists
        )
    except UndefinedError as err:
        msg = "Unable to create project directory '{}'".format(unrendered_dir)
        raise UndefinedVariableInTemplate(msg, err, context)

    # We want the Jinja path and the OS paths to match. Consequently, we'll:
    #   + CD to the template folder
    #   + Set Jinja's path to '.'
    #
    #  In order to build our files to the correct folder(s), we'll use an
    # absolute path for the target folder (project_dir)

    project_dir = os.path.abspath(project_dir)
    logger.debug('Project directory is {}'.format(project_dir))

    # if we created the output directory, then it's ok to remove it
    # if rendering fails
    delete_project_on_failure = output_directory_created

    _run_hook_from_repo_dir(
        repo_dir,
        'pre_gen_project',
        project_dir,
        context,
        delete_project_on_failure
    )

    with work_in(template_dir):
        env.loader = FileSystemLoader('.')

        for root, dirs, files in os.walk('.'):
            # We must separate the two types of dirs into different lists.
            # The reason is that we don't want ``os.walk`` to go through the
            # unrendered directories, since they will just be copied.
            copy_dirs = []
            render_dirs = []

            for d in dirs:
                d_ = os.path.normpath(os.path.join(root, d))
                # We check the full path, because that's how it can be
                # specified in the ``_copy_without_render`` setting, but
                # we store just the dir name
                if is_copy_only_path(d_, context):
                    copy_dirs.append(d)
                else:
                    render_dirs.append(d)

            for copy_dir in copy_dirs:
                indir = os.path.normpath(os.path.join(root, copy_dir))
                outdir = os.path.normpath(os.path.join(project_dir, indir))
                logger.debug(
                    'Copying dir {} to {} without rendering'
                    ''.format(indir, outdir)
                )
                shutil.copytree(indir, outdir)

            # We mutate ``dirs``, because we only want to go through these dirs
            # recursively
            dirs[:] = render_dirs
            for d in dirs:
                unrendered_dir = os.path.join(project_dir, root, d)
                try:
                    render_and_create_dir(
                        unrendered_dir,
                        context,
                        output_dir,
                        env,
                        overwrite_if_exists,
                        skip_if_file_exists
                    )
                except UndefinedError as err:
                    if delete_project_on_failure:
                        rmtree(project_dir)
                    _dir = os.path.relpath(unrendered_dir, output_dir)
                    msg = "Unable to create directory '{}'".format(_dir)
                    raise UndefinedVariableInTemplate(msg, err, context)

            for f in files:
                infile = os.path.normpath(os.path.join(root, f))
                if is_copy_only_path(infile, context):
                    outfile_tmpl = env.from_string(infile)
                    outfile_rendered = outfile_tmpl.render(**context)
                    outfile = os.path.join(project_dir, outfile_rendered)
                    logger.debug(
                        'Copying file {} to {} without rendering'
                        ''.format(infile, outfile)
                    )
                    shutil.copyfile(infile, outfile)
                    shutil.copymode(infile, outfile)
                    continue
                try:
                    generate_file(project_dir, infile, context, env, skip_if_file_exists)
                except UndefinedError as err:
                    if delete_project_on_failure:
                        rmtree(project_dir)
                    msg = "Unable to create file '{}'".format(infile)
                    raise UndefinedVariableInTemplate(msg, err, context)

    _run_hook_from_repo_dir(
        repo_dir,
        'post_gen_project',
        project_dir,
        context,
        delete_project_on_failure
    )

    return project_dir


1			# -- coding: utf-8 --
2
3			"""Functions for generating a project from a project template."""
4			from __future__ import unicode_literals
5
6			import fnmatch
7			import io
8			import json
9			import logging
10			import os
11			import shutil
12			from collections import OrderedDict
13
14			from binaryornot.check import is_binary
15			from jinja2 import FileSystemLoader
16			from jinja2.exceptions import TemplateSyntaxError, UndefinedError
17
18			from .environment import StrictEnvironment
19			from .exceptions import (
20			NonTemplatedInputDirException,
21			ContextDecodingException,
22			FailedHookException,
23			OutputDirExistsException,
24			UndefinedVariableInTemplate
25			)
26			from .find import find_template
27			from .hooks import run_hook
28			from .utils import make_sure_path_exists, work_in, rmtree
29
30			logger = logging.getLogger(__name__)
31
32
33			def is_copy_only_path(path, context):
34			"""Check whether the given `path` should only be copied and not rendered.
35
36			Returns True if `path` matches a pattern in the given `context` dict,
37			otherwise False.
38
39			:param path: A file-system path referring to a file or dir that
40			should be rendered or just copied.
41			:param context: cookiecutter context.
42			"""
43			try:
44			for dont_render in context['cookiecutter']['_copy_without_render']:
45			if fnmatch.fnmatch(path, dont_render):
46			return True
47			except KeyError:
48			return False
49
50			return False
51
52
53			def apply_overwrites_to_context(context, overwrite_context):
54			"""Modify the given context in place based on the overwrite_context."""
55			for variable, overwrite in overwrite_context.items():
56			if variable not in context:
57			# Do not include variables which are not used in the template
58			continue
59
60			context_value = context[variable]
61
62			if isinstance(context_value, list):
63			# We are dealing with a choice variable
64			if overwrite in context_value:
65			# This overwrite is actually valid for the given context
66			# Let's set it as default (by definition first item in list)
67			# see ``cookiecutter.prompt.prompt_choice_for_config``
68			context_value.remove(overwrite)
69			context_value.insert(0, overwrite)
70			else:
71			# Simply overwrite the value for this variable
72			context[variable] = overwrite
73
74
75			def generate_context(context_file='cookiecutter.json', default_context=None,
76			extra_context=None):
77			"""Generate the context for a Cookiecutter project template.
78
79			Loads the JSON file as a Python object, with key being the JSON filename.
80
81			:param context_file: JSON file containing key/value pairs for populating
82			the cookiecutter's variables.
83			:param default_context: Dictionary containing config to take into account.
84			:param extra_context: Dictionary containing configuration overrides
85			"""
86			context = {}
87
88			try:
89			with open(context_file) as file_handle:
90			obj = json.load(file_handle, object_pairs_hook=OrderedDict)
91			except ValueError as e:
92			# JSON decoding error. Let's throw a new exception that is more
93			# friendly for the developer or user.
94			full_fpath = os.path.abspath(context_file)
95			json_exc_message = str(e)
96			our_exc_message = (
97			'JSON decoding error while loading "{0}". Decoding'
98			' error details: "{1}"'.format(full_fpath, json_exc_message))
99			raise ContextDecodingException(our_exc_message)
100
101			# Add the Python object to the context dictionary
102			file_name = os.path.split(context_file)[1]
103			file_stem = file_name.split('.')[0]
104			context[file_stem] = obj
105
106			# Overwrite context variable defaults with the default context from the
107			# user's global config, if available
108			if default_context:
109			apply_overwrites_to_context(obj, default_context)
110			if extra_context:
111			apply_overwrites_to_context(obj, extra_context)
112
113			logger.debug('Context generated is {}'.format(context))
114			return context
115
116
117			def generate_file(project_dir, infile, context, env, skip_if_file_exists=False):
118			"""Render filename of infile as name of outfile, handle infile correctly.
119
120			Dealing with infile appropriately:
121
122			a. If infile is a binary file, copy it over without rendering.
123			b. If infile is a text file, render its contents and write the
124			rendered infile to outfile.
125
126			Precondition:
127
128			When calling `generate_file()`, the root template dir must be the
129			current working directory. Using `utils.work_in()` is the recommended
130			way to perform this directory change.
131
132			:param project_dir: Absolute path to the resulting generated project.
133			:param infile: Input file to generate the file from. Relative to the root
134			template dir.
135			:param context: Dict for populating the cookiecutter's variables.
136			:param env: Jinja2 template execution environment.
137			"""
138			logger.debug('Processing file {}'.format(infile))
139
140			# Render the path to the output file (not including the root project dir)
141			outfile_tmpl = env.from_string(infile)
142
143			outfile = os.path.join(project_dir, outfile_tmpl.render(**context))
144			file_name_is_empty = os.path.isdir(outfile)
145			if file_name_is_empty:
146			logger.debug('The resulting file name is empty: {0}'.format(outfile))
147			return
148
149			if skip_if_file_exists and os.path.exists(outfile):
150			logger.debug('The resulting file already exists: {0}'.format(outfile))
151			return
152
153			logger.debug('Created file at {0}'.format(outfile))
154
155			# Just copy over binary files. Don't render.
156			logger.debug("Check {} to see if it's a binary".format(infile))
157			if is_binary(infile):
158			logger.debug(
159			'Copying binary {} to {} without rendering'
160			''.format(infile, outfile)
161			)
162			shutil.copyfile(infile, outfile)
163			else:
164			# Force fwd slashes on Windows for get_template
165			# This is a by-design Jinja issue
166			infile_fwd_slashes = infile.replace(os.path.sep, '/')
167
168			# Render the file
169			try:
170			tmpl = env.get_template(infile_fwd_slashes)
171			except TemplateSyntaxError as exception:
172			# Disable translated so that printed exception contains verbose
173			# information about syntax error location
174			exception.translated = False
175			raise
176			rendered_file = tmpl.render(**context)
177
178			logger.debug('Writing contents to file {}'.format(outfile))
179
180			with io.open(outfile, 'w', encoding='utf-8') as fh:
181			fh.write(rendered_file)
182
183			# Apply file permissions to output file
184			shutil.copymode(infile, outfile)
185
186
187			def render_and_create_dir(dirname, context, output_dir, environment,
188			overwrite_if_exists=False, skip_if_file_exists=False):
189			"""Render name of a directory, create the directory, return its path."""
190			name_tmpl = environment.from_string(dirname)
191			rendered_dirname = name_tmpl.render(**context)
192
193			dir_to_create = os.path.normpath(
194			os.path.join(output_dir, rendered_dirname)
195			)
196
197			logger.debug('Rendered dir {} must exist in output_dir {}'.format(
198			dir_to_create,
199			output_dir
200			))
201
202			output_dir_exists = os.path.exists(dir_to_create)
203
204			if output_dir_exists:
205			if overwrite_if_exists:
206			logger.debug(
207			'Output directory {} already exists,'
208			'overwriting it'.format(dir_to_create)
209			)
210			else:
211			msg = 'Error: "{}" directory already exists'.format(dir_to_create)
212			raise OutputDirExistsException(msg)
213			else:
214			make_sure_path_exists(dir_to_create)
215
216			return dir_to_create, not output_dir_exists
217
218
219			def ensure_dir_is_templated(dirname):
220			"""Ensure that dirname is a templated directory name."""
221			if '{{' in dirname and '}}' in dirname:
222			return True
223			else:
224			raise NonTemplatedInputDirException
225
226
227			def _run_hook_from_repo_dir(repo_dir, hook_name, project_dir, context,
228			delete_project_on_failure):
229			"""Run hook from repo directory, clean project directory if hook fails.
230
231			:param repo_dir: Project template input directory.
232			:param hook_name: The hook to execute.
233			:param project_dir: The directory to execute the script from.
234			:param context: Cookiecutter project context.
235			:param delete_project_on_failure: Delete the project directory on hook
236			failure?
237			"""
238			with work_in(repo_dir):
239			try:
240			run_hook(hook_name, project_dir, context)
241			except FailedHookException:
242			if delete_project_on_failure:
243			rmtree(project_dir)
244			logger.error(
245			"Stopping generation because {} hook "
246			"script didn't exit successfully".format(hook_name)
247			)
248			raise
249
250
251			def generate_files(repo_dir, context=None, output_dir='.',
252			overwrite_if_exists=False, skip_if_file_exists=False):
253			"""Render the templates and saves them to files.
254
255			:param repo_dir: Project template input directory.
256			:param context: Dict for populating the template's variables.
257			:param output_dir: Where to output the generated project dir into.
258			:param overwrite_if_exists: Overwrite the contents of the output directory
259			if it exists.
260			"""
261			template_dir = find_template(repo_dir)
262			logger.debug('Generating project from {}...'.format(template_dir))
263			context = context or {}
264
265			unrendered_dir = os.path.split(template_dir)[1]
266			ensure_dir_is_templated(unrendered_dir)
267			env = StrictEnvironment(
268			context=context,
269			keep_trailing_newline=True,
270			)
271			try:
272			project_dir, output_directory_created = render_and_create_dir(
273			unrendered_dir,
274			context,
275			output_dir,
276			env,
277			overwrite_if_exists,
278			skip_if_file_exists
279			)
280			except UndefinedError as err:
281			msg = "Unable to create project directory '{}'".format(unrendered_dir)
282			raise UndefinedVariableInTemplate(msg, err, context)
283
284			# We want the Jinja path and the OS paths to match. Consequently, we'll:
285			# + CD to the template folder
286			# + Set Jinja's path to '.'
287			#
288			# In order to build our files to the correct folder(s), we'll use an
289			# absolute path for the target folder (project_dir)
290
291			project_dir = os.path.abspath(project_dir)
292			logger.debug('Project directory is {}'.format(project_dir))
293
294			# if we created the output directory, then it's ok to remove it
295			# if rendering fails
296			delete_project_on_failure = output_directory_created
297
298			_run_hook_from_repo_dir(
299			repo_dir,
300			'pre_gen_project',
301			project_dir,
302			context,
303			delete_project_on_failure
304			)
305
306			with work_in(template_dir):
307			env.loader = FileSystemLoader('.')
308
309			for root, dirs, files in os.walk('.'):
310			# We must separate the two types of dirs into different lists.
311			# The reason is that we don't want ``os.walk`` to go through the
312			# unrendered directories, since they will just be copied.
313			copy_dirs = []
314			render_dirs = []
315
316			for d in dirs:
317			d_ = os.path.normpath(os.path.join(root, d))
318			# We check the full path, because that's how it can be
319			# specified in the ``_copy_without_render`` setting, but
320			# we store just the dir name
321			if is_copy_only_path(d_, context):
322			copy_dirs.append(d)
323			else:
324			render_dirs.append(d)
325
326			for copy_dir in copy_dirs:
327			indir = os.path.normpath(os.path.join(root, copy_dir))
328			outdir = os.path.normpath(os.path.join(project_dir, indir))
329			logger.debug(
330			'Copying dir {} to {} without rendering'
331			''.format(indir, outdir)
332			)
333			shutil.copytree(indir, outdir)
334
335			# We mutate ``dirs``, because we only want to go through these dirs
336			# recursively
337			dirs[:] = render_dirs
338			for d in dirs:
339			unrendered_dir = os.path.join(project_dir, root, d)
340			try:
341			render_and_create_dir(
342			unrendered_dir,
343			context,
344			output_dir,
345			env,
346			overwrite_if_exists,
347			skip_if_file_exists
348			)
349			except UndefinedError as err:
350			if delete_project_on_failure:
351			rmtree(project_dir)
352			_dir = os.path.relpath(unrendered_dir, output_dir)
353			msg = "Unable to create directory '{}'".format(_dir)
354			raise UndefinedVariableInTemplate(msg, err, context)
355
356			for f in files:
357			infile = os.path.normpath(os.path.join(root, f))
358			if is_copy_only_path(infile, context):
359			outfile_tmpl = env.from_string(infile)
360			outfile_rendered = outfile_tmpl.render(**context)
361			outfile = os.path.join(project_dir, outfile_rendered)
362			logger.debug(
363			'Copying file {} to {} without rendering'
364			''.format(infile, outfile)
365			)
366			shutil.copyfile(infile, outfile)
367			shutil.copymode(infile, outfile)
368			continue
369			try:
370			generate_file(project_dir, infile, context, env, skip_if_file_exists)
371			except UndefinedError as err:
372			if delete_project_on_failure:
373			rmtree(project_dir)
374			msg = "Unable to create file '{}'".format(infile)
375			raise UndefinedVariableInTemplate(msg, err, context)
376
377			_run_hook_from_repo_dir(
378			repo_dir,
379			'post_gen_project',
380			project_dir,
381			context,
382			delete_project_on_failure
383			)
384
385			return project_dir
386

audreyr / cookiecutter

Pull Request — master (#1076)

generate_file() C

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Duplication

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Long Method

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