private void resetTrees() {
		inTree.setRootNode(new PendingRootNode());
		outTree.setRootNode(new PendingRootNode());
	}
NB: I think this is the real start of building the trees.
Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/decompiler/taint/TaintSliceTreeProvider.java