original_string: public function hasHeader($name)
      {
          $name = $this->normalizeHeaderName($name);
  
          return isset($this->_environment[$name]);
      }
code: public function hasHeader($name)
      {
          $name = $this->normalizeHeaderName($name);
  
          return isset($this->_environment[$name]);
      }
code_tokens: public function hasHeader ( $ name ) { $ name = $ this -> normalizeHeaderName ( $ name ) ; return isset ( $ this -> _environment [ $ name ] ) ; }
docstring: Check if a header is set in the request.
  
  @param string $name The header you want to get (case-insensitive)
  @return bool Whether or not the header is defined.
  @link http://www.php-fig.org/psr/psr-7/ This method is part of the PSR-7 server request interface.
docstring_tokens: Check if a header is set in the request .