code: public GridBagLayoutBuilder append(Component component, int colSpan, int rowSpan, boolean expandX, boolean expandY,
              Insets insets) {
          if (expandX && expandY)
              return append(component, colSpan, rowSpan, 1.0, 1.0, insets);
          else if (expandX)
              return append(component, colSpan, rowSpan, 1.0, 0.0, insets);
          else if (expandY)
              return append(component, colSpan, rowSpan, 0.0, 1.0, insets);
          else
              return append(component, colSpan, rowSpan, 0.0, 0.0, insets);
      }
docs: Appends the given component to the end of the current line
  
  @param component the component to add to the current line
  @param colSpan   the number of columns to span
  @param rowSpan   the number of rows to span
  @param expandX   should the component "grow" horrizontally?
  @param expandY   should the component "grow" vertically?
  @param insets    the insets to use for this component
  
  @return "this" to make it easier to string together append calls