code: @GET
      @Produces(MediaType.APPLICATION_JSON)
      public Response listAllPushApplications(@QueryParam("page") Integer page,
                                              @QueryParam("per_page") Integer pageSize,
                                              @QueryParam("includeDeviceCount") @DefaultValue("false") boolean includeDeviceCount,
                                              @QueryParam("includeActivity")    @DefaultValue("false") boolean includeActivity) {
          if (pageSize != null) {
              pageSize = Math.min(MAX_PAGE_SIZE, pageSize);
          } else {
              pageSize = DEFAULT_PAGE_SIZE;
          }
  
          if (page == null) {
              page = 0;
          }
  
          logger.trace("Query paged push applications with {} items for page {}", pageSize, page);
          final PageResult<PushApplication, Count> pageResult = getSearch().findAllPushApplicationsForDeveloper(page, pageSize);
          ResponseBuilder response = Response.ok(pageResult.getResultList());
          response.header("total", pageResult.getAggregate().getCount());
          for (PushApplication app : pageResult.getResultList()) {
              if (includeActivity) {
                  logger.trace("Include activity header");
                  putActivityIntoResponseHeaders(app, response);
              }
              if (includeDeviceCount) {
                  logger.trace("Include device count header");
                  putDeviceCountIntoResponseHeaders(app, response);
              }
          }
          return response.build();
      }
docs: List Push Applications
  
  @param page                  page number
  @param pageSize              number of items per page
  @param includeDeviceCount    put device count into response headers, default {@code false}
  @param includeActivity       put activity into response headers, default {@code false}
  @return                      list of {@link PushApplication}s
  
  @responseheader total                                Total count of items
  @responseheader activity_app_{pushApplicationID}     Count number of messages for Push Application
  @responseheader activity_variant_{variantID}         Count number of messages for Variant
  @responseheader deviceCount_app_{pushApplicationID}  Count number of devices for Push Application
  @responseheader deviceCount_variant_{variantID}      Count number of devices for Variant