def modify_instance_fleet(ClusterId=None, InstanceFleet=None):
    """
    Modifies the target On-Demand and target Spot capacities for the instance fleet with the specified InstanceFleetID within the cluster specified using ClusterID. The call either succeeds or fails atomically.
    See also: AWS API Documentation
    
    
    :example: response = client.modify_instance_fleet(
        ClusterId='string',
        InstanceFleet={
            'InstanceFleetId': 'string',
            'TargetOnDemandCapacity': 123,
            'TargetSpotCapacity': 123
        }
    )
    
    
    :type ClusterId: string
    :param ClusterId: [REQUIRED]
            The unique identifier of the cluster.
            

    :type InstanceFleet: dict
    :param InstanceFleet: [REQUIRED]
            The unique identifier of the instance fleet.
            InstanceFleetId (string) -- [REQUIRED]A unique identifier for the instance fleet.
            TargetOnDemandCapacity (integer) --The target capacity of On-Demand units for the instance fleet. For more information see InstanceFleetConfig$TargetOnDemandCapacity .
            TargetSpotCapacity (integer) --The target capacity of Spot units for the instance fleet. For more information, see InstanceFleetConfig$TargetSpotCapacity .
            

    """
    pass
