message: changed c header
diff: @@ -200,7 +200,10 @@ pub extern fn cxs_connection_connect(connection_handle: u32, connection_options:
  #[no_mangle]
  #[allow(unused_variables, unused_mut)]
  -pub extern fn cxs_connection_serialize(connection_handle: u32, Option<extern fn(xclaim_handle: u32, err: u32, claim_state: *const c_char)>) -> *mut c_char {
  +pub extern fn cxs_connection_serialize(connection_handle: u32, cb: Option<extern fn(xconnection_handle: u32, err: u32, claim_state: *const c_char)>) -> *mut c_char {
  + check_useful_c_callback!(cb, error::INVALID_OPTION.code_num);
  +
  +
  let json_string = to_string(connection_handle);
  if json_string.is_empty() {
  