@Override
		public void run(TaskMonitor monitor) {
			try {
				domainFile.delete(versionNumber);
			}
			catch (IOException e) {
				ClientUtil.handleException(tool.getProject().getRepository(), e, "Delete Version",
					VersionHistoryPanel.this);
			}
		}
Set up the drag and drop stuff.
Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionHistoryPanel.java