public function header($name, $value = null)
    {
        if (!is_null($value)) {
            $this[$name] = $value;
        }

        return $this[$name];
    }
public function header($name, $value = null)
    {
        if (!is_null($value)) {
            $this[$name] = $value;
        }

        return $this[$name];
    }
public function header ( $ name , $ value = null ) { if ( ! is_null ( $ value ) ) { $ this [ $ name ] = $ value ; } return $ this [ $ name ] ; }
Get and set header
@param  string      $name  Header name
@param  string|null $value Header value
@return string      Header value
Get and set header