FreeOpcUa / opcua-asyncio

        return member_keys

def indent(elem, level=0):

    """

    copy and paste from http://effbot.org/zone/element-lib.htm#prettyprint

    it basically walks your tree and adds spaces and newlines so the tree is

    printed in a nice way

    """

    i = "\n" + level * "  "

    if len(elem):

        if not elem.text or not elem.text.strip():

            elem.text = i + "  "

        if not elem.tail or not elem.tail.strip():

            elem.tail = i

        for elem in elem:

            indent(elem, level + 1)

        if not elem.tail or not elem.tail.strip():

            elem.tail = i

    else:

        if level and (not elem.tail or not elem.tail.strip()):

            elem.tail = i

        # Et.dump(self.etree.getroot())

        return Et.tostring(self.etree.getroot(), encoding='utf-8')

    def indent(self, elem, level=0):

        i = '\n' + level * '  '

        if len(elem):

            if not elem.text or not elem.text.strip():

                elem.text = i + '  '

            if not elem.tail or not elem.tail.strip():

                elem.tail = i

            for elem in elem:

                self.indent(elem, level + 1)

            if not elem.tail or not elem.tail.strip():

                elem.tail = i

        else:

            if level and (not elem.tail or not elem.tail.strip()):

                elem.tail = i

def _reference_generator(source_id, target_id, reference_type, is_forward=True):