Function select

select(wgt, start, end): void
Selects all text of the specified widget. It invokes the select method, if any, of the widget. It does nothing if the method doesn't exist.
Parameters
- wgt: Widget<HTMLElement> & {
  select?(s, e): any;
  }
  the widget.
- start: number
  the starting index of the selection range
- end: number
  the ending index of the selection range (excluding). In other words, the text between start and (end-1) is selected.
Returns void