public DataTypeManager getProgramDataTypeManager() {
		DataTypeManager[] managers = getDataTypeManagers();
		for (DataTypeManager manager : managers) {
			if (manager instanceof ProgramDataTypeManager) {
				return manager;
			}
		}
		return null;
	}
Create the actions for the menu on the tool.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/DataTypeManagerPlugin.java