original_string: public function toString(array $opts = array())
      {
          $eol = empty($opts['canonical'])
              ? $this->_eol
              : "\r\n";
          $text = '';
  
          foreach ($this->toArray($opts) as $key => $val) {
              foreach ((is_array($val) ? $val : array($val)) as $entry) {
                  $text .= $key . ': ' . $entry . $eol;
              }
          }
  
          return $text . $eol;
      }
code: public function toString(array $opts = array())
      {
          $eol = empty($opts['canonical'])
              ? $this->_eol
              : "\r\n";
          $text = '';
  
          foreach ($this->toArray($opts) as $key => $val) {
              foreach ((is_array($val) ? $val : array($val)) as $entry) {
                  $text .= $key . ': ' . $entry . $eol;
              }
          }
  
          return $text . $eol;
      }
code_tokens: public function toString ( array $ opts = array ( ) ) { $ eol = empty ( $ opts [ 'canonical' ] ) ? $ this -> _eol : "\r\n" ; $ text = '' ; foreach ( $ this -> toArray ( $ opts ) as $ key => $ val ) { foreach ( ( is_array ( $ val ) ? $ val : array ( $ val ) ) as $ entry ) { $ text .= $ key . ': ' . $ entry . $ eol ; } } return $ text . $ eol ; }
docstring: Returns all headers concatenated into a single string.
  
  @param array $opts  See toArray().
  
  @return string  The headers in string format.
docstring_tokens: Returns all headers concatenated into a single string .