Generate GraphQL query

def get_gql_query(self):
        """Generate GraphQL query"""
        template_string = """query(
            $stops: [String],
            $quays: [String],
            $whitelist: InputWhiteListed,
            $numberOfDepartures: Int = 2,
            $omitNonBoarding: Boolean = true){\n"""
        if self.stops:
            template_string += GRAPHQL_STOP_TEMPLATE
        if self.quays:
            template_string += GRAPHQL_QUAY_TEMPLATE
        template_string += "}"
        template_string += GRAPHQL_CALL_FRAGMENT

        return template_string