Custom Array for Json argument parser

[Bxmnx]

I'm attempting to create a custom array type for argument parsing in the json body. So I created a function and created a schema for it:

type_services.__schema__ = {'type':'array','items':{'type':'string'}} 

and create it with

testparser.add_argument(name='services',type=type_services,location='json',required=True)

The type seems to work correctly, when I parse the arguments I get a list of strings. However, it doesn't show it as a field in the json body within the swagger documentation. With that being the only parameter is the json body is being shown as '{}'

When checking the swagger.json, it the items type seems to be missing. I added a "firstName" parameter string for comparison and this is the what I get in the swagger.json

"/customer/test": {
            "parameters": [
                {
                    "name": "payload",
                    "required": true,
                    "in": "body",
                    "schema": {
                        "type": "object",
                        "properties": {
                            "firstName": {
                                "type": "string"
                            },
                            "services": {
                                "type": "array"
                            }
                        }
                    }
                }
            ],
            "post": {
                "responses": {
                    "200": {
                        "description": "Success"
                    }
                },
                "operationId": "post_create",
                "tags": [
                    "customer"
                ]
            }
        }
    },

The type: string portion is missing in the schema. Any suggestions?