code: public GridBagLayoutBuilder appendLeftLabel(String labelKey, int colSpan) {
          final JLabel label = createLabel(labelKey);
          label.setHorizontalAlignment(SwingConstants.LEFT);
          return appendLabel(label, colSpan);
      }
docs: Appends a left-justified label to the end of the given line, using the
  provided string as the key to look in the
  {@link #setComponentFactory(ComponentFactory) ComponentFactory's}message
  bundle for the text to use.
  
  @param labelKey the key into the message bundle; if not found the key is used
  as the text to display
  @param colSpan  the number of columns to span
  
  @return "this" to make it easier to string together append calls