def describe_raid_arrays(InstanceId=None, StackId=None, RaidArrayIds=None):
    """
    Describe an instance's RAID arrays.
    See also: AWS API Documentation
    
    
    :example: response = client.describe_raid_arrays(
        InstanceId='string',
        StackId='string',
        RaidArrayIds=[
            'string',
        ]
    )
    
    
    :type InstanceId: string
    :param InstanceId: The instance ID. If you use this parameter, DescribeRaidArrays returns descriptions of the RAID arrays associated with the specified instance.

    :type StackId: string
    :param StackId: The stack ID.

    :type RaidArrayIds: list
    :param RaidArrayIds: An array of RAID array IDs. If you use this parameter, DescribeRaidArrays returns descriptions of the specified arrays. Otherwise, it returns a description of every array.
            (string) --
            

    :rtype: dict
    :return: {
        'RaidArrays': [
            {
                'RaidArrayId': 'string',
                'InstanceId': 'string',
                'Name': 'string',
                'RaidLevel': 123,
                'NumberOfDisks': 123,
                'Size': 123,
                'Device': 'string',
                'MountPoint': 'string',
                'AvailabilityZone': 'string',
                'CreatedAt': 'string',
                'StackId': 'string',
                'VolumeType': 'string',
                'Iops': 123
            },
        ]
    }
    
    
    """
    pass
