private void recalcWidthCache() {
		totalColumnWidth = 0;
		for (TableColumn tableColumn : visibleColumns.getColumns()) {
			totalColumnWidth += tableColumn.getWidth();
		}
	}
Recalculates the total combined width of all columns.  Updates the
<code>totalColumnWidth</code> property.
Ghidra/Framework/Docking/src/main/java/docking/widgets/table/GTableColumnModel.java