code: public GridBagLayoutBuilder append(Component component, int colSpan, int rowSpan, double xweight, double yweight) {
          return append(component, colSpan, rowSpan, xweight, yweight, defaultInsets);
      }
docs: Appends the given component to the end of the current line, using the
  default insets
  
  @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 xweight   the "growth weight" horrizontally
  @param yweight   the "growth weight" horrizontally
  
  @return "this" to make it easier to string together append calls
  
  @see GridBagConstraints#weightx
  @see GridBagConstraints#weighty