code: private function isValidVariable(Tokens $tokens, $index)
      {
          if (!$tokens[$index]->isGivenKind(T_VARIABLE)) {
              return false;
          }
  
          $nextIndex = $tokens->getNextMeaningfulToken($index);
  
          return $tokens[$nextIndex]->equals('=');
      }
docs: Checks variable assignments for correct docblock usage.
  
  @param Tokens $tokens
  @param int    $index  index of variable Token
  
  @return bool