private TransitionPoints getTransitionPoint(Map<FGVertex, TransitionPoints> transitionPoints,
			Map<FGVertex, Point2D> destinationLocations, FGVertex vertex) {
		TransitionPoints transtionPoint = transitionPoints.get(vertex);
		if (transtionPoint != null) {
			return transtionPoint;
		}

		// We have a destination vertex that is not being moved, so it is not
		// in the 'transitionPoints'.  Create a TransitionPoint for it.
		return createTransitionPoint(destinationLocations, vertex);
	}
Constructor - used when updating an existing group

@param controller the controller of the graph to be ungrouped
@param groupVertex The group vertex to be ungrouped
@param verticesToGroup the vertices to combine into a group
@param useAnimation whether to use animation
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/util/job/GroupVertexFunctionGraphJob.java