private void createAndShowProvider(Function function) {
		CallTreeProvider provider = new CallTreeProvider(this, false);

		CallTreeOptions callTreeOptions = primaryProvider.getCallTreeOptions();
		provider.setCallTreeOptions(callTreeOptions);

		providers.add(provider);
		provider.initialize(currentProgram, function);
		tool.showComponentProvider(provider, true);
	}
Assuming a function <b>foo</b>, this plugin will show:
 1) all callers of <b>foo</b> 
 2) all functions which reference <b>foo</b>
 3) all callees of <b>foo</b>
 4) all functions referenced by <b>foo</b>.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/calltree/CallTreePlugin.java