json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "pubsub push subscription request",
      "description": "pubsub push subscription request",
      "type": "object",
      "properties": {
          "message": {
              "type": "object",
              "properties": {
                  "attributes": {
                      "patternProperties": {
                          "^[A-Za-z0-9_\\-]+$": {
                              "type": "string",
                              "minLength": 1
                          }
                      }
                  },
                  "data": {
                      "type": "string",
                      "minLength": 1
                  },
                  "publish_time": {
                      "type": "string",
                      "minLength": 1
                  },
                  "publishTime": {
                      "type": "string",
                      "minLength": 1
                  },
                  "message_id": {
                      "type": "string",
                      "minLength": 1
                  },
                  "messageId": {
                      "type": "string",
                      "minLength": 1
                  }
              },
              "required": [
                  "attributes",
                  "data",
                  "message_id",
                  "messageId",
                  "publish_time",
                  "publishTime"
              ],
              "additionalProperties": false
          },
          "subscription": {
              "type": "string",
              "minLength": 1
          }
      },
      "required": [
          "message",
          "subscription"
      ],
      "additionalProperties": false
  }