@Override
	public int compareTo(CodeBlockVertex o) {
		if (codeBlock == null) {
			return 1;
		}
		if (o.codeBlock == null) {
			return -1;
		}
		return codeBlock.getMinAddress().compareTo(o.codeBlock.getMinAddress());
	}
Returns true if this vertex is not backed by a code block.
@return true if this vertex is not backed by a code block.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/block/graph/CodeBlockVertex.java