code: def _setup_api_format_checker_tests(self, app, format_checker=None):
      class IPAddress(restplus.fields.Raw):
          __schema_type__ = "string"
          __schema_format__ = "ipv4"
  
      api = restplus.Api(app, format_checker=format_checker)
      model = api.model("MyModel", {"ip": IPAddress(required=True)})
  
      @api.route("/format_checker/")
      class TestResource(restplus.Resource):
          @api.expect(model, validate=True)
          def post(self):
              return {}
  
imports: from __future__ import unicode_literals
  import flask_restplus
label_desc: Use image node_id 6 for calling the PayloadTest obj's underlying member method code with example usage: obj._setup_api_format_checker_tests(app, format_checker) and returns: dict