code: public ApiSuccessResponse attachUserData(String id, UserDataOperationId userData) throws ApiException {
          ApiResponse<ApiSuccessResponse> resp = attachUserDataWithHttpInfo(id, userData);
          return resp.getData();
      }
docs: Attach user data to a call
  Attach the provided data to the specified call. This adds the data to the call even if data already exists with the provided keys.
  @param id The connection ID of the call. (required)
  @param userData The data to attach to the call. This is an array of objects with the properties key, type, and value. (required)
  @return ApiSuccessResponse
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body