Complex classes like BaseCollection 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 BaseCollection, and based on these observations, apply Extract Interface, too.
1 | <?php |
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11 | class BaseCollection implements \Iterator, \ArrayAccess, \Countable { |
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12 | |||
13 | /** |
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14 | * @var int |
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15 | */ |
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16 | protected $position = 0; |
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17 | |||
18 | /** |
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19 | * Array of objects |
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20 | * |
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21 | * @var array |
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22 | */ |
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23 | protected $items = []; |
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24 | |||
25 | |||
26 | /** |
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27 | * @param array $items |
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28 | */ |
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29 | public function __construct(array $items = []) { |
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36 | |||
37 | |||
38 | /** |
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39 | * |
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40 | */ |
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41 | public function __clone() { |
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48 | |||
49 | |||
50 | /** |
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51 | * Return number of items in this collection |
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52 | * |
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53 | * @return int |
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54 | */ |
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55 | public function count() { |
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58 | |||
59 | |||
60 | /** |
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61 | * Add one item to begin of collection |
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62 | * This item is accessible via `$collection->getFirst();` |
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63 | * |
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64 | * @param $item |
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65 | * @return $this |
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66 | */ |
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67 | public function prepend(Token $item) { |
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71 | |||
72 | |||
73 | /** |
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74 | * Add one item to the end of collection |
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75 | * This item is accessible via `$collection->getLast();` |
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76 | * |
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77 | * @param $item |
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78 | * @return $this |
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79 | */ |
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80 | public function append(Token $item) { |
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84 | |||
85 | |||
86 | /** |
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87 | * @param int $index |
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88 | * @param array $items |
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89 | * @return $this |
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90 | * @throws \InvalidArgumentException |
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91 | */ |
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92 | public function addAfter($index, $items) { |
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113 | |||
114 | |||
115 | /** |
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116 | * Truncate current list of items and add new |
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117 | * |
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118 | * @param array $items |
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119 | * @return $this |
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120 | */ |
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121 | public function setItems($items) { |
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136 | |||
137 | |||
138 | /** |
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139 | * Remove part of items from collection |
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140 | * Works as array_slice |
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141 | * |
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142 | * |
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143 | * @param $offset |
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144 | * @param null $length |
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145 | * @return $this |
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146 | */ |
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147 | public function slice($offset, $length = null) { |
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151 | |||
152 | |||
153 | /** |
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154 | * Take part of items and return new collection |
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155 | * Works as array_slice |
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156 | * At this point items in 2 collection is same |
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157 | * |
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158 | * @param int $offset |
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159 | * @param null $length |
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160 | * @return self |
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161 | */ |
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162 | public function extractItems($offset, $length = null) { |
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170 | |||
171 | |||
172 | /** |
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173 | * Rewind current collection |
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174 | */ |
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175 | public function rewind() { |
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179 | |||
180 | |||
181 | /** |
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182 | * Return last item from collection |
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183 | * |
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184 | * @return mixed |
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185 | */ |
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186 | public function getLast() { |
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189 | |||
190 | |||
191 | /** |
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192 | * Return first item from collection |
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193 | * @return mixed |
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194 | */ |
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195 | public function getFirst() { |
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198 | |||
199 | |||
200 | /** |
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201 | * Return next item from current |
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202 | * Also can return item with position from current + $step |
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203 | * |
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204 | * @param int $step |
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205 | * @return mixed |
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206 | */ |
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207 | public function getNext($step = 1) { |
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211 | |||
212 | |||
213 | /** |
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214 | * Return previous item |
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215 | * Also can return previous from current position + $step |
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216 | * |
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217 | * @param int $step |
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218 | * @return mixed |
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219 | */ |
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220 | public function getPrevious($step = 1) { |
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224 | |||
225 | |||
226 | /** |
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227 | * Return current item in collection |
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228 | * |
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229 | * @return object |
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230 | */ |
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231 | public function current() { |
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234 | |||
235 | |||
236 | /** |
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237 | * Return current position |
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238 | * |
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239 | * @return int |
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240 | */ |
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241 | public function key() { |
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244 | |||
245 | |||
246 | /** |
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247 | * Switch to next position |
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248 | */ |
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249 | public function next() { |
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252 | |||
253 | |||
254 | /** |
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255 | * Check if item exist in current position |
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256 | * |
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257 | * @return bool |
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258 | */ |
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259 | public function valid() { |
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262 | |||
263 | |||
264 | /** |
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265 | * Add item to the end or modify item with given key |
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266 | * |
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267 | * @param int|null $offset |
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268 | * @param object $item |
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269 | * @return $this |
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270 | */ |
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271 | public function offsetSet($offset, $item) { |
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288 | |||
289 | |||
290 | /** |
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291 | * Check if item with given offset exists |
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292 | * |
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293 | * @param mixed $offset |
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294 | * @return bool |
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295 | */ |
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296 | public function offsetExists($offset) { |
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299 | |||
300 | |||
301 | /** |
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302 | * Remove item from collection |
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303 | * |
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304 | * @param int $offset |
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305 | */ |
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306 | public function offsetUnset($offset) { |
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309 | |||
310 | |||
311 | /** |
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312 | * Get item from collection |
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313 | * |
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314 | * @param int $offset |
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315 | * @return object |
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316 | */ |
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317 | public function offsetGet($offset) { |
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320 | |||
321 | |||
322 | /** |
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323 | * Return array of items connected to this collection |
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324 | * |
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325 | * Rewrite this method in you class |
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326 | * |
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327 | * <code> |
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328 | * foreach($collection->getTokens() as $item){ |
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329 | * echo get_class($item)."\n; |
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330 | * } |
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331 | * </code> |
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332 | * @return Token[] |
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333 | */ |
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334 | public function getTokens() : array { |
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337 | |||
338 | |||
339 | public function getItems() { |
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343 | |||
344 | |||
345 | /** |
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346 | * Iterate over objects in collection |
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347 | * |
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348 | * <code> |
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349 | * $collection->each(function($item, $index, $collection){ |
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350 | * if ( $index > 0 ) { |
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351 | * $item->remove(); |
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352 | * } |
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353 | * }) |
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354 | * </code> |
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355 | * |
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356 | * @param callable $callback |
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357 | * @return $this |
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358 | * @throws \InvalidArgumentException |
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359 | */ |
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360 | public function each(callable $callback) : self { |
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374 | |||
375 | |||
376 | public function map(callable $callback) { |
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380 | |||
381 | |||
382 | /** |
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383 | * @param int $index |
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384 | */ |
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385 | protected function validateIndex($index) { |
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388 | |||
389 | |||
390 | } |
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.