Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Stream often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Stream, and based on these observations, apply Extract Interface, too.
1 | <?php |
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22 | class Stream implements StreamInterface |
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23 | { |
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24 | |||
25 | /** |
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26 | * @var resource |
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27 | */ |
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28 | protected $resource; |
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29 | |||
30 | /** |
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31 | * @var string|resource |
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32 | */ |
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33 | protected $stream; |
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34 | |||
35 | /** |
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36 | * @param string|resource $stream |
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37 | * @param string $mode Mode with which to open stream |
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38 | * @throws InvalidArgumentException |
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39 | */ |
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40 | 274 | public function __construct($stream, $mode = 'r') |
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44 | |||
45 | /** |
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46 | * Reads all data from the stream into a string, from the beginning to end. |
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47 | * |
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48 | * This method MUST attempt to seek to the beginning of the stream before |
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49 | * reading data and read the stream until the end is reached. |
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50 | * |
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51 | * Warning: This could attempt to load a large amount of data into memory. |
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52 | * |
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53 | * This method MUST NOT raise an exception in order to conform with PHP's |
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54 | * string casting operations. |
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55 | * |
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56 | * @see http://php.net/manual/en/language.oop5.magic.php#object.tostring |
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57 | * @return string |
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58 | */ |
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59 | 8 | public function __toString() |
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74 | |||
75 | /** |
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76 | * Closes the stream and any underlying resources. |
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77 | * |
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78 | * @return void |
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79 | */ |
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80 | 6 | public function close() |
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88 | |||
89 | /** |
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90 | * Separates any underlying resources from the stream. |
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91 | * |
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92 | * After the stream has been detached, the stream is in an unusable state. |
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93 | * |
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94 | * @return resource|null Underlying PHP stream, if any |
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95 | */ |
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96 | 26 | public function detach() |
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102 | |||
103 | /** |
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104 | * Attach a new stream/resource to the instance. |
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105 | * |
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106 | * @param string|resource $resource |
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107 | * @param string $mode |
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108 | * @throws InvalidArgumentException for stream identifier that cannot be |
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109 | * cast to a resource |
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110 | * @throws InvalidArgumentException for non-resource stream |
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111 | */ |
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112 | 32 | public function attach($resource, $mode = 'r') |
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116 | |||
117 | /** |
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118 | * Get the size of the stream if known. |
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119 | * |
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120 | * @return int|null Returns the size in bytes if known, or null if unknown. |
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121 | */ |
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122 | 6 | public function getSize() |
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130 | |||
131 | /** |
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132 | * Returns the current position of the file read/write pointer |
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133 | * |
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134 | * @return int Position of the file pointer |
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135 | * @throws \RuntimeException on error. |
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136 | */ |
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137 | 8 | public function tell() |
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138 | { |
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139 | 8 | if (!$this->resource) { |
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140 | 2 | throw new RuntimeException( |
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141 | 1 | 'No resource available; cannot tell position' |
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142 | 1 | ); |
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143 | } |
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144 | 6 | $result = ftell($this->resource); |
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145 | 6 | if (!is_int($result)) { |
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146 | throw new RuntimeException( |
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147 | 'Error occurred during tell operation' |
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148 | ); |
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149 | } |
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150 | 6 | return $result; |
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151 | } |
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152 | |||
153 | /** |
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154 | * Returns true if the stream is at the end of the stream. |
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155 | * |
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156 | * @return bool |
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157 | */ |
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158 | 8 | public function eof() |
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166 | |||
167 | /** |
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168 | * Returns whether or not the stream is seekable. |
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169 | * |
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170 | * @return bool |
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171 | */ |
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172 | 20 | public function isSeekable() |
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181 | |||
182 | /** |
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183 | * Seek to a position in the stream. |
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184 | * |
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185 | * @link http://www.php.net/manual/en/function.fseek.php |
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186 | * @param int $offset Stream offset |
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187 | * @param int $whence Specifies how the cursor position will be calculated |
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188 | * based on the seek offset. Valid values are identical to the built-in |
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189 | * PHP $whence values for `fseek()`. SEEK_SET: Set position equal to |
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190 | * offset bytes SEEK_CUR: Set position to current location plus offset |
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191 | * SEEK_END: Set position to end-of-stream plus offset. |
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192 | * @throws \RuntimeException on failure. |
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193 | * |
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194 | * @return bool |
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195 | */ |
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196 | 18 | public function seek($offset, $whence = SEEK_SET) |
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210 | |||
211 | /** |
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212 | * Seek to the beginning of the stream. |
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213 | * |
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214 | * If the stream is not seekable, this method will raise an exception; |
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215 | * otherwise, it will perform a seek(0). |
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216 | * |
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217 | * @see seek() |
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218 | * @link http://www.php.net/manual/en/function.fseek.php |
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219 | * @throws \RuntimeException on failure. |
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220 | * |
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221 | * @return bool |
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222 | */ |
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223 | 12 | public function rewind() |
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227 | |||
228 | /** |
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229 | * Returns whether or not the stream is writable. |
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230 | * |
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231 | * @return bool |
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232 | */ |
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233 | 80 | public function isWritable() |
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248 | |||
249 | /** |
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250 | * Write data to the stream. |
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251 | * |
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252 | * @param string $string The string that is to be written. |
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253 | * @return int Returns the number of bytes written to the stream. |
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254 | * @throws \RuntimeException on failure. |
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255 | */ |
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256 | 34 | View Code Duplication | public function write($string) |
270 | |||
271 | /** |
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272 | * Returns whether or not the stream is readable. |
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273 | * |
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274 | * @return bool |
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275 | */ |
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276 | 64 | public function isReadable() |
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285 | |||
286 | /** |
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287 | * Read data from the stream. |
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288 | * |
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289 | * @param int $length Read up to $length bytes from the object and return |
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290 | * them. Fewer than $length bytes may be returned if underlying stream |
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291 | * call returns fewer bytes. |
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292 | * @return string Returns the data read from the stream, or an empty string |
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293 | * if no bytes are available. |
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294 | * @throws \RuntimeException if an error occurs. |
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295 | */ |
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296 | 6 | View Code Duplication | public function read($length) |
310 | |||
311 | /** |
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312 | * Returns the remaining contents in a string |
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313 | * |
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314 | * @return string |
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315 | * @throws \RuntimeException if unable to read or an error occurs while |
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316 | * reading. |
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317 | */ |
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318 | 12 | public function getContents() |
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329 | |||
330 | /** |
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331 | * Get stream metadata as an associative array or retrieve a specific key. |
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332 | * |
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333 | * The keys returned are identical to the keys returned from PHP's |
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334 | * stream_get_meta_data() function. |
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335 | * |
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336 | * @link http://php.net/manual/en/function.stream-get-meta-data.php |
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337 | * @param string $key Specific metadata to retrieve. |
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338 | * @return array|mixed|null Returns an associative array if no key is |
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339 | * provided. Returns a specific key value if a key is provided and the |
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340 | * value is found, or null if the key is not found. |
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341 | */ |
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342 | 6 | public function getMetadata($key = null) |
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353 | |||
354 | /** |
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355 | * Set the internal stream resource. |
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356 | * |
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357 | * @param string|resource $stream String stream target or stream resource. |
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358 | * @param string $mode Resource mode for stream target. |
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359 | * @throws InvalidArgumentException for invalid streams or resources. |
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360 | */ |
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361 | 274 | private function setStream($stream, $mode = 'r') |
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391 | } |