def METHOD_NAME(gateway_id: Optional[pulumi.Input[str]] = None,
                       resource_group_name: Optional[pulumi.Input[str]] = None,
                       service_name: Optional[pulumi.Input[str]] = None,
                       opts: Optional[pulumi.InvokeOptions] = None) -> pulumi.Output[GetGatewayResult]:
    """
    Gets the details of the Gateway specified by its identifier.
    Azure REST API version: 2022-08-01.
    :param str gateway_id: Gateway entity identifier. Must be unique in the current API Management service instance. Must not have value 'managed'
    :param str resource_group_name: The name of the resource group. The name is case insensitive.
    :param str service_name: The name of the API Management service.
    """
    ...