Complex classes like Cursor 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 Cursor, and based on these observations, apply Extract Interface, too.
1 | <?php |
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14 | class Cursor |
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15 | { |
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16 | const INDENT_LEVEL = 4; |
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17 | |||
18 | /** |
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19 | * @var string |
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20 | */ |
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21 | private $line; |
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22 | |||
23 | /** |
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24 | * @var int |
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25 | */ |
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26 | private $length; |
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27 | |||
28 | /** |
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29 | * @var int |
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30 | * |
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31 | * It's possible for this to be 1 char past the end, meaning we've parsed all chars and have |
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32 | * reached the end. In this state, any character-returning method MUST return null. |
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33 | */ |
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34 | private $currentPosition = 0; |
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35 | |||
36 | /** |
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37 | * @var int |
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38 | */ |
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39 | private $column = 0; |
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40 | |||
41 | /** |
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42 | * @var int |
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43 | */ |
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44 | private $indent = 0; |
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45 | |||
46 | /** |
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47 | * @var int |
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48 | */ |
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49 | private $previousPosition = 0; |
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50 | |||
51 | /** |
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52 | * @var int|null |
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53 | */ |
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54 | private $nextNonSpaceCache; |
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55 | |||
56 | /** |
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57 | * @var bool |
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58 | */ |
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59 | private $partiallyConsumedTab = false; |
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60 | |||
61 | /** |
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62 | * @var string |
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63 | */ |
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64 | private $encoding; |
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65 | |||
66 | /** |
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67 | * @var bool |
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68 | */ |
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69 | private $lineContainsTabs; |
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70 | |||
71 | /** |
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72 | * @var bool |
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73 | */ |
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74 | private $isMultibyte; |
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75 | |||
76 | /** |
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77 | * @var int |
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78 | */ |
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79 | private $charCache = []; |
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80 | |||
81 | /** |
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82 | * @param string $line |
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83 | */ |
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84 | 2391 | public function __construct($line, $encoding = 'UTF-8') |
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92 | |||
93 | /** |
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94 | * Returns the position of the next character which is not a space (or tab) |
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95 | * |
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96 | * @return int |
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97 | */ |
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98 | 2118 | public function getNextNonSpacePosition() |
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124 | |||
125 | /** |
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126 | * Returns the next character which isn't a space (or tab) |
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127 | * |
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128 | * @return string |
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129 | */ |
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130 | 1911 | public function getNextNonSpaceCharacter() |
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134 | |||
135 | /** |
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136 | * Calculates the current indent (number of spaces after current position) |
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137 | * |
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138 | * @return int |
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139 | */ |
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140 | 1998 | public function getIndent() |
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148 | |||
149 | /** |
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150 | * Whether the cursor is indented to INDENT_LEVEL |
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151 | * |
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152 | * @return bool |
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153 | */ |
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154 | 1938 | public function isIndented() |
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158 | |||
159 | /** |
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160 | * @param int|null $index |
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161 | * |
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162 | * @return string|null |
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163 | */ |
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164 | 2172 | public function getCharacter($index = null) |
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181 | |||
182 | /** |
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183 | * Returns the next character (or null, if none) without advancing forwards |
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184 | * |
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185 | * @param int $offset |
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186 | * |
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187 | * @return string|null |
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188 | */ |
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189 | 1020 | public function peek($offset = 1) |
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193 | |||
194 | /** |
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195 | * Whether the remainder is blank |
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196 | * |
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197 | * @return bool |
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198 | */ |
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199 | 1956 | public function isBlank() |
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203 | |||
204 | /** |
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205 | * Move the cursor forwards |
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206 | */ |
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207 | 795 | public function advance() |
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211 | |||
212 | /** |
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213 | * Move the cursor forwards |
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214 | * |
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215 | * @param int $characters Number of characters to advance by |
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216 | * @param bool $advanceByColumns Whether to advance by columns instead of spaces |
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217 | */ |
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218 | 2247 | public function advanceBy($characters, $advanceByColumns = false) |
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272 | |||
273 | /** |
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274 | * Advances the cursor by a single space or tab, if present |
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275 | * |
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276 | * @return bool |
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277 | */ |
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278 | 339 | public function advanceBySpaceOrTab() |
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290 | |||
291 | /** |
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292 | * Parse zero or more space/tab characters |
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293 | * |
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294 | * @return int Number of positions moved |
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295 | */ |
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296 | 1848 | public function advanceToNextNonSpaceOrTab() |
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304 | |||
305 | /** |
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306 | * Parse zero or more space characters, including at most one newline. |
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307 | * |
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308 | * Tab characters are not parsed with this function. |
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309 | * |
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310 | * @return int Number of positions moved |
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311 | */ |
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312 | 441 | public function advanceToNextNonSpaceOrNewline() |
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329 | |||
330 | /** |
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331 | * Move the position to the very end of the line |
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332 | * |
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333 | * @return int The number of characters moved |
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334 | */ |
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335 | 84 | public function advanceToEnd() |
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344 | |||
345 | /** |
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346 | * @return string |
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347 | */ |
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348 | 2043 | public function getRemainder() |
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364 | |||
365 | /** |
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366 | * @return string |
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367 | */ |
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368 | 1887 | public function getLine() |
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372 | |||
373 | /** |
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374 | * @return bool |
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375 | */ |
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376 | 411 | public function isAtEnd() |
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380 | |||
381 | /** |
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382 | * Try to match a regular expression |
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383 | * |
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384 | * Returns the matching text and advances to the end of that match |
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385 | * |
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386 | * @param string $regex |
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387 | * |
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388 | * @return string|null |
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389 | */ |
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390 | 1908 | public function match($regex) |
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416 | |||
417 | /** |
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418 | * Encapsulates the current state of this cursor in case you need to rollback later. |
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419 | * |
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420 | * WARNING: Do not parse or use the return value for ANYTHING except for |
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421 | * passing it back into restoreState(), as the number of values and their |
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422 | * contents may change in any future release without warning. |
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423 | * |
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424 | * @return array |
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425 | */ |
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426 | 1011 | public function saveState() |
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437 | |||
438 | /** |
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439 | * Restore the cursor to a previous state. |
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440 | * |
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441 | * Pass in the value previously obtained by calling saveState(). |
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442 | * |
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443 | * @param array $state |
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444 | */ |
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445 | 795 | public function restoreState($state) |
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456 | |||
457 | /** |
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458 | * @return int |
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459 | */ |
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460 | 648 | public function getPosition() |
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464 | |||
465 | /** |
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466 | * @return string |
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467 | */ |
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468 | 870 | public function getPreviousText() |
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472 | |||
473 | /** |
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474 | * @return int |
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475 | */ |
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476 | 240 | public function getColumn() |
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480 | } |
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481 |