docs: @GET
      @Path("/{pushAppID}/count")
      @Produces(MediaType.APPLICATION_JSON)
      public Response countInstallations(@PathParam("pushAppID") String pushApplicationID) {
  
          logger.trace("counting devices by type for push application '{}'", pushApplicationID);
          Map<String, Long> result = pushAppService.countInstallationsByType(pushApplicationID);
          return Response.ok(result).build();
      }