@Override
		public void domainFileChanged(DomainObject object) {
			remove(key);
		}
DomainObjectFileListener for programs in the cache. If a program instance has its DomainFile 
changed (e.g., 'Save As' action), then the cache mapping is incorrect as it sill has the
program instance associated with its old DomainFile. So we need to add a listener to 
recognize when this occurs. If it does, we simply remove the entry from the cache. Also,
we need to remove any programs from the cache if changes are made to avoid questions about
who is responsible for saving changed programs that only live in the cache.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/ProgramCache.java