boolean isValid(Object versionTag) {
		if (group == null) {
			return true;
		}

		if (module != null) {
			return versionTag == module.getVersionTag();
		}
		return true;
	}
Clear fields so this object can be garbage collected.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramNode.java