original_string: public function hasFeature($feature)
      {
          $feature = strtoupper($feature);
  
          if (!isset($this->features[$feature])) {
              return null;
          }
  
          return $this->features[$feature];
      }
code: public function hasFeature($feature)
      {
          $feature = strtoupper($feature);
  
          if (!isset($this->features[$feature])) {
              return null;
          }
  
          return $this->features[$feature];
      }
code_tokens: public function hasFeature ( $ feature ) { $ feature = strtoupper ( $ feature ) ; if ( ! isset ( $ this -> features [ $ feature ] ) ) { return null ; } return $ this -> features [ $ feature ] ; }
docstring: Check if feature exists and enabled.
  
  @param string $feature
  
  @return bool|null
docstring_tokens: Check if feature exists and enabled .