@Override
	public int compareTo(FcgLevel l2) {

		int result = getDirection().compareTo(l2.getDirection());
		if (result != 0) {
			return result; // compare by direction first In on top; Out on bottom
		}

		// same direction, use row
		return -(getRelativeRow() - l2.getRelativeRow());
	}
Returns the row of this vertex 
@return the row of this vertex
Ghidra/Features/GraphFunctionCalls/src/main/java/functioncalls/graph/FcgLevel.java