code: public function isGlobalFunctionCall(Tokens $tokens, $index)
      {
          if (!$tokens[$index]->isGivenKind(T_STRING)) {
              return false;
          }
  
          $prevIndex = $tokens->getPrevMeaningfulToken($index);
          if ($tokens[$prevIndex]->isGivenKind(T_NS_SEPARATOR)) {
              $prevIndex = $tokens->getPrevMeaningfulToken($prevIndex);
          }
  
          $nextIndex = $tokens->getNextMeaningfulToken($index);
  
          return !$tokens[$prevIndex]->isGivenKind([T_DOUBLE_COLON, T_FUNCTION, CT::T_NAMESPACE_OPERATOR, T_NEW, T_OBJECT_OPERATOR, CT::T_RETURN_REF, T_STRING])
              && $tokens[$nextIndex]->equals('(');
      }
docs: @param Tokens $tokens
  @param int    $index
  
  @return bool