@Override
	void mapFileID(String fileId, Item item) {
		getFileIdMap().put(fileId, item);
	}
Construct existing indexed filesystem with an empty index.
This can be used to prepare for rebuilding the filesystem index.
@param rootPath
@throws IOException
Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/IndexedV1LocalFileSystem.java