code: protected function applyFix(\SplFileInfo $file, Tokens $tokens)
      {
          static $nativeFunctionNames = null;
  
          if (null === $nativeFunctionNames) {
              $nativeFunctionNames = $this->getNativeFunctionNames();
          }
  
          for ($index = 0, $count = $tokens->count(); $index < $count; ++$index) {
              // test if we are at a function all
              if (!$tokens[$index]->isGivenKind(T_STRING)) {
                  continue;
              }
  
              $next = $tokens->getNextMeaningfulToken($index);
              if (!$tokens[$next]->equals('(')) {
                  $index = $next;
  
                  continue;
              }
  
              $functionNamePrefix = $tokens->getPrevMeaningfulToken($index);
              if ($tokens[$functionNamePrefix]->isGivenKind([T_DOUBLE_COLON, T_NEW, T_OBJECT_OPERATOR, T_FUNCTION, CT::T_RETURN_REF])) {
                  continue;
              }
  
              if ($tokens[$functionNamePrefix]->isGivenKind(T_NS_SEPARATOR)) {
                  // skip if the call is to a constructor or to a function in a namespace other than the default
                  $prev = $tokens->getPrevMeaningfulToken($functionNamePrefix);
                  if ($tokens[$prev]->isGivenKind([T_STRING, T_NEW])) {
                      continue;
                  }
              }
  
              // test if the function call is to a native PHP function
              $lower = strtolower($tokens[$index]->getContent());
              if (!\array_key_exists($lower, $nativeFunctionNames)) {
                  continue;
              }
  
              $tokens[$index] = new Token([T_STRING, $nativeFunctionNames[$lower]]);
              $index = $next;
          }
      }
docs: {@inheritdoc}