def describe_stack_summary(StackId=None):
    """
    Describes the number of layers and apps in a specified stack, and the number of instances in each state, such as running_setup or online .
    See also: AWS API Documentation
    
    
    :example: response = client.describe_stack_summary(
        StackId='string'
    )
    
    
    :type StackId: string
    :param StackId: [REQUIRED]
            The stack ID.
            

    :rtype: dict
    :return: {
        'StackSummary': {
            'StackId': 'string',
            'Name': 'string',
            'Arn': 'string',
            'LayersCount': 123,
            'AppsCount': 123,
            'InstancesCount': {
                'Assigning': 123,
                'Booting': 123,
                'ConnectionLost': 123,
                'Deregistering': 123,
                'Online': 123,
                'Pending': 123,
                'Rebooting': 123,
                'Registered': 123,
                'Registering': 123,
                'Requested': 123,
                'RunningSetup': 123,
                'SetupFailed': 123,
                'ShuttingDown': 123,
                'StartFailed': 123,
                'Stopped': 123,
                'Stopping': 123,
                'Terminated': 123,
                'Terminating': 123,
                'Unassigning': 123
            }
        }
    }
    
    
    """
    pass
