Desktop GUI - Widgets - Collapsible pane

From pyswarm

Some domain classes may contain many attributes, thus complete windows presenting all of them may get too massive for the user to be presented all together at the same time.

In order to hide groups of (related) attributes, the developer can use one or more collapsible panes in such window. Each collapsible pane may have a label (like a heading).

Collapsed example:

By clicking on the label (or a specific button if more appropriate) the pane will be expanded - and vice versa: