dragstart: Fires once the pointer, pressed on a feature, moves a few pixels.drag: Fires on every move until the pointer is released, the first right after dragstart.dragend: Fires once when the pointer is released, a second finger touches, the touch is
cancelled, or the map's events are disabled.A handler for any of them makes the features it covers draggable:
click, and a drag fires no click.The handler gets the feature pressed at dragstart, and the pointer's current position. The SDK
moves nothing: show the feature again at that position to move it.
Subtype for drag events, with the mouse or a single finger.