code: public FluentSelect deselectAll() {
          executeAndWrapReThrowIfNeeded(new DeselectAll(), Context.singular(context, "deselectAll"), true);
          return new FluentSelect(super.delegate, currentElement.getFound(), this.context, monitor, booleanInsteadOfNotFoundException);
      }
docs: Clear all selected entries. This is only valid when the SELECT supports multiple selections.
  
  @throws UnsupportedOperationException If the SELECT does not support multiple selections