public int minCol() {
		// handle case when grid is empty
		if (minCol > maxCol) {
			return 0;
		}
		return minCol;
	}
Shifts the columns bounds by the given amount
@param rowShift the amount to shift the row bounds.
@param colShift the amount to shift the column bounds.
@throws IllegalArgumentException if the shift would make the minimum column negative
Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/layout/GridBounds.java