@Override
	public synchronized void close() {
		if (project != null) {
			project.getProjectData().removeDomainFolderChangeListener(this);
			for (IndexInfo index : indexes) {
				index.indexedFiles.clear();
			}
			project = null;
			indexListeners.clear();

			Thread localIndexThread = indexThread;
			if (localIndexThread != null && localIndexThread.isAlive()) {
				localIndexThread.interrupt();
			}
		}
	}
@param indexType IndexType enum
@param mappingFunc bifunc that returns value that will be used to lookup the file
@param indexedFiles map of index keyvalue to fileId (either string or list of strings)
Ghidra/Features/Base/src/main/java/ghidra/plugin/importer/ProjectIndexService.java