public boolean isTreeEmpty() {
		if (gTree == null) {
			return true;
		}
		return (gTree.getTotalNum() == 0);
	}
Check whether the instruction tree is empty
@return {@code true} precisely when the instruction tree is null or empty
Ghidra/Features/BytePatterns/src/main/java/ghidra/bitpatterns/gui/InstructionSequenceTreePanelBuilder.java