MDM Java API 2 - CheckoutRecordsCommand not implemented

Hi

When I want to use the CheckoutRecordsCommand I get this exception:

"com.sap.mdm.internal.protocol.manual.ServerException: Noch nicht implementiert" (not implemented yet).

We have the newest patches of all components installed (Server 5.5.42.57, API 5.5.42.48 SP05 Patch 2).

Now I have two questions:

1) Does anybody know if and when this is planned to be implemented?

2) Is there any other way of locking records from the Java API 2? Are there any workarounds?

Thank you!