PhpCsFixer\Tokenizer\Tokens::getPrevMeaningfulToken PHP Method

    public function getPrevMeaningfulToken($index)
    {
        return $this->getMeaningfulTokenSibling($index, -1);
    }

 /**
  * @param Tokens $tokens
  * @param int    $index
  *
  * @return int
  */
 private function findStart(Tokens $tokens, $index)
 {
     do {
         $index = $tokens->getPrevMeaningfulToken($index);
         $token = $tokens[$index];
         $blockType = $tokens->detectBlockType($token);
         if (null !== $blockType && !$blockType['isStart']) {
             $index = $tokens->findBlockEnd($blockType['type'], $index, false);
             $token = $tokens[$index];
         }
     } while (!$token->equalsAny(array('$', array(T_VARIABLE))));
     $prevIndex = $tokens->getPrevMeaningfulToken($index);
     $prevToken = $tokens[$prevIndex];
     if ($prevToken->equals('$')) {
         $index = $prevIndex;
         $prevIndex = $tokens->getPrevMeaningfulToken($index);
         $prevToken = $tokens[$prevIndex];
     }
     if ($prevToken->isGivenKind(T_OBJECT_OPERATOR)) {
         return $this->findStart($tokens, $prevIndex);
     }
     if ($prevToken->isGivenKind(T_PAAMAYIM_NEKUDOTAYIM)) {
         $prevPrevIndex = $tokens->getPrevMeaningfulToken($prevIndex);
         if (!$tokens[$prevPrevIndex]->isGivenKind(T_STRING)) {
             return $this->findStart($tokens, $prevIndex);
         }
         $index = $tokens->getTokenNotOfKindSibling($prevIndex, -1, array(array(T_NS_SEPARATOR), array(T_STRING)));
         $index = $tokens->getNextMeaningfulToken($index);
     }
     return $index;
 }