def METHOD_NAME():
    client = boto3.client("dms", region_name="us-east-1")
    client.create_replication_task(
        ReplicationTaskIdentifier="test",
        SourceEndpointArn="source-endpoint-arn",
        TargetEndpointArn="target-endpoint-arn",
        ReplicationInstanceArn="replication-instance-arn",
        MigrationType="full-load",
        TableMappings='{"rules":[]}',
    )
    with pytest.raises(ClientError) as ex:
        client.create_replication_task(
            ReplicationTaskIdentifier="test",
            SourceEndpointArn="source-endpoint-arn",
            TargetEndpointArn="target-endpoint-arn",
            ReplicationInstanceArn="replication-instance-arn",
            MigrationType="full-load",
            TableMappings='{"rules":[]}',
        )
    assert ex.value.operation_name == "CreateReplicationTask"
    assert ex.value.response["Error"]["Code"] == "ResourceAlreadyExistsFault"
    assert (
        ex.value.response["Error"]["Message"]
        == "The resource you are attempting to create already exists."
    )