code: public ApiSuccessResponse addDocument(String mediatype, String id, AddDocumentData addDocumentData) throws ApiException {
          ApiResponse<ApiSuccessResponse> resp = addDocumentWithHttpInfo(mediatype, id, addDocumentData);
          return resp.getData();
      }
docs: Add an attachment to the open-media interaction
  Add an attachment to the interaction specified in the id path parameter
  @param mediatype media-type of interaction to add attachment (required)
  @param id id of interaction (required)
  @param addDocumentData  (required)
  @return ApiSuccessResponse
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body