code: public ApiSuccessResponse attachMediaUserData(String mediatype, String id, UserDataOperationId userData) throws ApiException {
          ApiResponse<ApiSuccessResponse> resp = attachMediaUserDataWithHttpInfo(mediatype, id, userData);
          return resp.getData();
      }
docs: Attach user data to an interaction
  Attach the provided data to the specified interaction.
  @param mediatype The media channel. (required)
  @param id The ID of the interaction. (required)
  @param userData The data to attach to the interaction. 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