def METHOD_NAME(self):
    if self.config.get("custom_reports_fields"):
        properties = {
            field.strip(): {"type": ["null", "string"]}
            for field in convert_custom_reports_fields_to_list(self.config.get("custom_reports_fields", ""))
        }
    else:
        properties = {}
    return {
        "$schema": "http://json-schema.org/draft-07/schema#",
        "type": "object",
        "properties": properties,
    }