public boolean isShowingLocation(ProgramLocation location) {
		if (currentFunction == null) {
			return false;
		}

		AddressSetView body = currentFunction.getBody();
		return body.contains(location.getAddress());
	}
NB: This is key as well.

this is called in the doSetFunction method
Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/decompiler/taint/TaintSliceTreeProvider.java