original_string: public function getHeader($header): string
      {
          if ($this->hasHeader($header)) {
              return implode(', ', $this->headers[$header]);
          }
          return '';
      }
code: public function getHeader($header): string
      {
          if ($this->hasHeader($header)) {
              return implode(', ', $this->headers[$header]);
          }
          return '';
      }
code_tokens: public function getHeader ( $ header ) : string { if ( $ this -> hasHeader ( $ header ) ) { return implode ( ', ' , $ this -> headers [ $ header ] ) ; } return '' ; }
docstring: Retrieve a header by the given case-insensitive name as a string
  
  This method returns all of the header values of the given
  case-insensitive header name as a string concatenated together using
  a comma.
  
  @param  string $header case-insensitive header name.
  
  @return string
docstring_tokens: Retrieve a header by the given case - insensitive name as a string