JSON sent:
{"app_id":"7b1a67e9-da57-4686-9f15-37a32c12e860","included_segments":["empty"],"data":{"foo":"bar"},"collapse_id":"kkk","ttl":0,"android_group_message":{"en":""},"android_background_data":true,"priority":10}
JSON sent:
{"app_id":"da31988a-8d3a-4d4c-942d-74e8167593c4","included_segments":["empty"],"data":{"foo":"bar"},"collapse_id":"kkk","ttl":0,"android_group_message":{"en":""},"android_background_data":true,"priority":10}
JSON sent:
{"app_id":"b1303c5a-b6dc-49b6-9342-5fde1dcb98f1","included_segments":["empty"],"data":{"foo":"bar"},"collapse_id":"kkk","ttl":0,"android_group_message":{"en":""},"android_background_data":true,"priority":10}
JSON sent:
{"app_id":"5b284a34-fef6-4e7d-9ea3-c18289d9adc3","included_segments":["empty"],"data":{"foo":"bar"},"collapse_id":"kkk","ttl":0,"android_group_message":{"en":""},"android_background_data":true,"priority":10}
JSON sent:
{"app_id":"dde6503c-adf4-41c7-b870-8bc11e8e22f0","included_segments":["empty"],"data":{"foo":"bar"},"collapse_id":"kkk","ttl":0,"android_group_message":{"en":""},"android_background_data":true,"priority":10}

JSON received:
{"allresponses":"{\"id\":\"\",\"errors\":[\"All included players are not subscribed\"]}{\"id\":\"\",\"errors\":[\"All included players are not subscribed\"]}{\"id\":\"\",\"errors\":[\"All included players are not subscribed\"]}{\"id\":\"\",\"errors\":[\"All included players are not subscribed\"]}{\"id\":\"\",\"errors\":[\"All included players are not subscribed\"]}"}