public ProgramLocation getProgramLocation(MarkerLocation loc) {
		return null;
	}
Called when the navigation bar to the right of the window is clicked to allow the 
creator of a Marker an opportunity to provide a more specific ProgramLocation for
navigation. If null is specified, the client will navigate to the corresponding address.
@param loc the marker location
@return the desired location; may be null
Ghidra/Features/Base/src/main/java/ghidra/app/services/MarkerDescriptor.java