Custom code blocks can be represented either by an arbitrary selection, or code constructs not marked with
the folding toggles (for example, if or while).
To fold an arbitrary selected block
Select contiguous fragment of code in the editor.
On the main menu, choose Code | Folding | Fold Selection / Remove Region,
or press Ctrl+PeriodCtrl+PeriodCtrl+PeriodCtrl+PeriodCtrl+PeriodCtrl+PeriodCtrl+PeriodCtrl+PeriodCommand PeriodCommand PeriodCommand Period