def modify_spot_fleet_request(SpotFleetRequestId=None, TargetCapacity=None,
    ExcessCapacityTerminationPolicy=None):
    """
    Modifies the specified Spot fleet request.
    While the Spot fleet request is being modified, it is in the modifying state.
    To scale up your Spot fleet, increase its target capacity. The Spot fleet launches the additional Spot instances according to the allocation strategy for the Spot fleet request. If the allocation strategy is lowestPrice , the Spot fleet launches instances using the Spot pool with the lowest price. If the allocation strategy is diversified , the Spot fleet distributes the instances across the Spot pools.
    To scale down your Spot fleet, decrease its target capacity. First, the Spot fleet cancels any open bids that exceed the new target capacity. You can request that the Spot fleet terminate Spot instances until the size of the fleet no longer exceeds the new target capacity. If the allocation strategy is lowestPrice , the Spot fleet terminates the instances with the highest price per unit. If the allocation strategy is diversified , the Spot fleet terminates instances across the Spot pools. Alternatively, you can request that the Spot fleet keep the fleet at its current size, but not replace any Spot instances that are interrupted or that you terminate manually.
    See also: AWS API Documentation
    
    Examples
    This example increases the target capacity of the specified Spot fleet request.
    Expected Output:
    This example decreases the target capacity of the specified Spot fleet request without terminating any Spot Instances as a result.
    Expected Output:
    
    :example: response = client.modify_spot_fleet_request(
        SpotFleetRequestId='string',
        TargetCapacity=123,
        ExcessCapacityTerminationPolicy='noTermination'|'default'
    )
    
    
    :type SpotFleetRequestId: string
    :param SpotFleetRequestId: [REQUIRED]
            The ID of the Spot fleet request.
            

    :type TargetCapacity: integer
    :param TargetCapacity: The size of the fleet.

    :type ExcessCapacityTerminationPolicy: string
    :param ExcessCapacityTerminationPolicy: Indicates whether running Spot instances should be terminated if the target capacity of the Spot fleet request is decreased below the current size of the Spot fleet.

    :rtype: dict
    :return: {
        'Return': True|False
    }
    
    
    """
    pass
