Hello Mischa Müller,
Unfortunately this feature is currently not available. It is added to our to-do list however the release plan for the upcoming Q2 release (Mid July) is full and I am afraid there is a little chance that we would be able to squeeze it in. I'll push the priority of the feature and hopefully it will be available much sooner than Q3.
Let us know if we can do anything else to help.
the Telerik team
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