@Override
		public void versionDeleted(int version) {
			synchronized (fileSystem) {
				try {
					historyMgr.versionDeleted(version, deleteUser);
				}
				catch (IOException e) {
					Msg.error(this, "Failed to update version history: " + getPathName(), e);
				}
			}
		}
<code>LocalVersionedDbListener</code> provides a listener 
which maintains checkout and history data in response to 
VersionedDatabase callbacks.
Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/LocalDatabaseItem.java