public List<Integer> getColOffsets() {
		ArrayList<Integer> list = new ArrayList<>();
		for (Column<V> column : columnsByIndex.values()) {
			list.add(column.x);
		}
		return list;
	}
Returns the rows in this location map, sorted from lowest index to highest 

@return the rows in this location map, sorted from lowest index to highest
Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/layout/LayoutLocationMap.java