public function asArray()
    {
        $headers = [];
        foreach (array_filter($this->storage) as $header => $value) {
            $headers[] = $header . ': ' . $value;
        }

        return $headers;
    }
public function asArray()
    {
        $headers = [];
        foreach (array_filter($this->storage) as $header => $value) {
            $headers[] = $header . ': ' . $value;
        }

        return $headers;
    }
public function asArray ( ) { $ headers = [ ] ; foreach ( array_filter ( $ this -> storage ) as $ header => $ value ) { $ headers [ ] = $ header . ': ' . $ value ; } return $ headers ; }
Builds array of headers

@return array
Builds array of headers