updateDocker = function(docker){
			if (!docker._dockedShape || !docker._dockedShapeBounds)
				return;
			var off = {
			    x: docker._dockedShape.bounds.a.x - docker._dockedShapeBounds.a.x,
			    y: docker._dockedShape.bounds.a.y - docker._dockedShapeBounds.a.y
			};
			docker.bounds.moveBy(off);
			docker._dockedShapeBounds.moveBy(off);
		}
Move the first and last docker and calls the refresh method.
Attention: This does not calculates intersection point between the
edge and the bounded nodes. This only works if only the nodes are
moves.