public static extern void hw_set_body(IntPtr response, ref HaywireString body);
public static extern void hw_set_response_status_code(IntPtr response, ref HaywireString status_code);
public static extern void hw_set_response_header(IntPtr response, ref HaywireString name, ref HaywireString value);
public static extern HaywireString hw_get_header(ref HttpRequest request, ref HaywireString key);