Complex classes like MessageBody 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 MessageBody, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 20 | class MessageBody implements StreamInterface |
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| 21 | { |
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| 22 | /** |
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| 23 | * Modes in which a stream is readable |
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| 24 | * |
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| 25 | * @var array |
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| 26 | * @link http://php.net/manual/function.fopen.php |
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| 27 | */ |
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| 28 | protected static $readableModes = array('r', 'r+', 'w+', 'a+', 'x+', 'c+'); |
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| 29 | |||
| 30 | /** |
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| 31 | * Modes in which a stream is writable |
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| 32 | * |
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| 33 | * @var array |
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| 34 | * @link http://php.net/manual/function.fopen.php |
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| 35 | */ |
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| 36 | protected static $writableModes = array('r+', 'w', 'w+', 'a', 'a+', 'x', 'x+', 'c', 'c+'); |
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| 37 | |||
| 38 | /** |
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| 39 | * The stream underlying the message body |
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| 40 | * |
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| 41 | * @var resource |
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| 42 | */ |
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| 43 | protected $stream; |
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| 44 | |||
| 45 | /** |
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| 46 | * The underlying stream's metadata |
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| 47 | * |
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| 48 | * @var null|array |
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| 49 | */ |
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| 50 | protected $metadata; |
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| 51 | |||
| 52 | /** |
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| 53 | * Is the underlying stream readable? |
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| 54 | * |
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| 55 | * @var bool |
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| 56 | */ |
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| 57 | protected $readable; |
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| 58 | |||
| 59 | /** |
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| 60 | * Is the underlying stream writable? |
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| 61 | * |
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| 62 | * @var bool |
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| 63 | */ |
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| 64 | protected $writable; |
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| 65 | |||
| 66 | /** |
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| 67 | * Is the underlying stream seekable? |
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| 68 | * |
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| 69 | * @var bool |
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| 70 | */ |
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| 71 | protected $seekable; |
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| 72 | |||
| 73 | /** |
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| 74 | * Create a new message body with the provided stream underlying it. |
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| 75 | * |
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| 76 | * @param resource $stream |
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| 77 | */ |
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| 78 | public function __construct($stream) |
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| 88 | |||
| 89 | /** |
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| 90 | * Attach a resource to this message body. |
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| 91 | * |
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| 92 | * @param resource $stream |
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| 93 | */ |
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| 94 | public function attach($stream) |
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| 110 | |||
| 111 | /** |
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| 112 | * Separates any underlying resources from the stream. |
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| 113 | * |
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| 114 | * After the stream has been detached, the stream is in an unusable state. |
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| 115 | * |
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| 116 | * @return resource|null Underlying PHP stream, if any |
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| 117 | */ |
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| 118 | public function detach() |
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| 125 | |||
| 126 | /** |
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| 127 | * Check if a stream resource is already attached to this message body. |
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| 128 | * |
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| 129 | * @return bool |
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| 130 | */ |
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| 131 | public function isAttached() |
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| 135 | |||
| 136 | /** |
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| 137 | * Set the metadata state information on this object, sourced from the stream metadata. |
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| 138 | * |
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| 139 | * @param resource $stream |
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| 140 | */ |
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| 141 | protected function setMetadata($stream) |
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| 166 | |||
| 167 | /** |
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| 168 | * Get the size of the stream if known |
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| 169 | * |
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| 170 | * @return int|null Returns the size in bytes if known, or null if unknown. |
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| 171 | */ |
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| 172 | public function getSize() |
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| 181 | |||
| 182 | /** |
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| 183 | * Returns the current position of the file read/write pointer |
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| 184 | * |
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| 185 | * @return int|bool Position of the file pointer or false on error. |
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| 186 | */ |
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| 187 | public function tell() |
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| 191 | |||
| 192 | /** |
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| 193 | * Returns true if the stream is at the end of the stream. |
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| 194 | * |
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| 195 | * @return bool |
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| 196 | */ |
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| 197 | public function eof() |
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| 201 | |||
| 202 | /** |
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| 203 | * Returns whether or not the stream is seekable. |
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| 204 | * |
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| 205 | * @return bool |
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| 206 | */ |
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| 207 | public function isSeekable() |
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| 211 | |||
| 212 | /** |
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| 213 | * Seek to a position in the stream. |
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| 214 | * |
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| 215 | * @link http://www.php.net/manual/en/function.fseek.php |
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| 216 | * @param int $offset Stream offset |
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| 217 | * @param int $whence Specifies how the cursor position will be calculated |
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| 218 | * based on the seek offset. Valid values are identical to the built-in |
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| 219 | * PHP $whence values for `fseek()`. SEEK_SET: Set position equal to |
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| 220 | * offset bytes SEEK_CUR: Set position to current location plus offset |
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| 221 | * SEEK_END: Set position to end-of-stream plus offset. |
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| 222 | * @return bool Returns TRUE on success or FALSE on failure. |
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| 223 | */ |
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| 224 | public function seek($offset, $whence = SEEK_SET) |
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| 230 | |||
| 231 | /** |
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| 232 | * Seek to the beginning of the stream. |
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| 233 | * |
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| 234 | * If the stream is not seekable, this method will return FALSE, indicating |
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| 235 | * failure; otherwise, it will perform a seek(0), and return the status of |
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| 236 | * that operation. |
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| 237 | * |
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| 238 | * @see seek() |
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| 239 | * @link http://www.php.net/manual/en/function.fseek.php |
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| 240 | * @return bool Returns TRUE on success or FALSE on failure. |
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| 241 | */ |
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| 242 | public function rewind() |
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| 246 | |||
| 247 | /** |
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| 248 | * Returns whether or not the stream is writable. |
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| 249 | * |
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| 250 | * @return bool |
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| 251 | */ |
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| 252 | public function isWritable() |
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| 256 | |||
| 257 | /** |
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| 258 | * Write data to the stream. |
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| 259 | * |
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| 260 | * @param string $string The string that is to be written. |
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| 261 | * @return int|bool Returns the number of bytes written to the stream on |
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| 262 | * success or FALSE on failure. |
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| 263 | */ |
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| 264 | public function write($string) |
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| 268 | |||
| 269 | /** |
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| 270 | * Returns whether or not the stream is readable. |
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| 271 | * |
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| 272 | * @return bool |
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| 273 | */ |
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| 274 | public function isReadable() |
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| 278 | |||
| 279 | /** |
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| 280 | * Read data from the stream. |
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| 281 | * |
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| 282 | * @param int $length Read up to $length bytes from the object and return |
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| 283 | * them. Fewer than $length bytes may be returned if underlying stream |
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| 284 | * call returns fewer bytes. |
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| 285 | * @return string|false Returns the data read from the stream, false if |
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| 286 | * unable to read or if an error occurs. |
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| 287 | */ |
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| 288 | public function read($length) |
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| 292 | |||
| 293 | /** |
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| 294 | * Returns the remaining contents in a string |
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| 295 | * |
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| 296 | * @return string |
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| 297 | */ |
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| 298 | public function getContents() |
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| 302 | |||
| 303 | /** |
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| 304 | * Get stream metadata as an associative array or retrieve a specific key. |
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| 305 | * |
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| 306 | * The keys returned are identical to the keys returned from PHP's |
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| 307 | * stream_get_meta_data() function. |
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| 308 | * |
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| 309 | * @link http://php.net/manual/en/function.stream-get-meta-data.php |
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| 310 | * @param string $key Specific metadata to retrieve. |
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| 311 | * @return array|mixed|null Returns an associative array if no key is |
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| 312 | * provided. Returns a specific key value if a key is provided and the |
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| 313 | * value is found, or null if the key is not found. |
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| 314 | */ |
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| 315 | public function getMetadata($key = null) |
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| 323 | |||
| 324 | /** |
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| 325 | * Closes the stream and any underlying resources. |
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| 326 | * |
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| 327 | * @return void |
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| 328 | */ |
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| 329 | public function close() |
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| 333 | |||
| 334 | /** |
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| 335 | * Read the entire contents of the message body into a PHP string. |
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| 336 | * |
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| 337 | * @return string |
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| 338 | */ |
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| 339 | public function __toString() |
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| 343 | } |
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| 344 |