protected function setContent($content)
    {
        $this->content = (string) $content;

        if (empty($this->content)) {
            throw new \Exception('Header content is empty !');
        }

        return $this;
    }
protected function setContent($content)
    {
        $this->content = (string) $content;

        if (empty($this->content)) {
            throw new \Exception('Header content is empty !');
        }

        return $this;
    }
protected function setContent ( $ content ) { $ this -> content = ( string ) $ content ; if ( empty ( $ this -> content ) ) { throw new \ Exception ( 'Header content is empty !' ) ; } return $ this ; }
Set header content

@param  string $content
@return self
@throws \Exception
Set header content