jsx: Markers - end time and duration

Hello all,

I am making an extension panel to Adobe Premiere Pro and trying to insert markers programatically. However I wonder if I understand correctly the correlation between end and duration for a marker. The markers get created and the data is there, but duration is set to 0. I am expecting the duration of the marker to be marker.end - marker.start. Even if I insert markers from the PProPanel where end is set to a value, duration of the inserted markers is still 0. From the PProPanel examples I am using:

var tempTime = new Time(); // Use a local time object to take care of all the tick math

var newCommentMarker = markers.createMarker(12.345);
newCommentMarker.name = 'Marker created by PProPanel.';
newCommentMarker.comments = 'Here are some comments, inserted by PProPanel.';
tempTime.seconds = 15.6789;
newCommentMarker.end.ticks = tempTime.ticks;

Thank you in advance