void dispose() {
		program = null;
		listing = null;
		module = null;
		fragment = null;
		group = null;
		parentModule = null;
		path = null;
		groupPath = null;
	}
Clear fields so this object can be garbage collected.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramNode.java