@Override
	public String toString() {

		//@formatter:off
		return getClass().getSimpleName() + "{\n" +
			"\tcolumn: " + index + ",\n" +
			"\tx: " + x + ",\n" +
			"\twidth: " + width + ",\n" +
			"\tpadded width: " + getPaddedWidth(false) + "\n" +
		"}";
		//@formatter:on
	}
The grid index of this column (0, 1...n) for the number of columns
Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/layout/Column.java