docs: function () {
              // By default, keepFocus is false, unless it is set to true later:
              this._keepFocus = false;
              if (this._dropdownPopup) {
                  var calendarFocus = this._calendarFocus;
  
                  if (this._hasFocus && !calendarFocus) {
                      // passing the focus from the text field to the icon
                      this._keepFocus = true;
                  }
                  // override the focus method so that calling focus on the DatePicker while it is open
                  // actually focuses the dropdown icon
                  // focusing the DatePicker while the popup is open means focusing the dropdown icon
                  if (!calendarFocus) {
                      this.controller.getCalendar().focus();
                  }
              } else {
                  if (this._hasFocus && this._calendarFocus) {
                      // passing the focus from the icon to the text field
                      this._keepFocus = true;
                  }
                  // do the normal action otherwise:
                  this.$DropDownTextInput.focus.apply(this, arguments);
              }
          }