setSpeed() - Bad argument list

Hi,

with the QE-Version of the SDK, I was not able to use the clip.setSpeed()-Function correctly.

My code sample looks like this:

app.enableQE();
var as = qe.project.getActiveSequence();
var track0 = as.getVideoTrackAt(0);
var clip = track0.getItemAt(0);
clip.setSpeed(...)

I did not find any correct argument list for this.

Beside this special case: Is there any way, I could gatter this data by myself? There are a lot undocumented functions with missing argument lists I would love to use...

Thank you!

Best,

Sebastian