fix(datepicker): fix production build issue #5730

Author: daniloff200

src/datepicker/base/bs-datepicker-container.ts

@@ -23,6 +23,7 @@ export abstract class BsDatepickerAbstractComponent {
 
   _effects: BsDatepickerEffects;
   customRanges: BsCustomDates[] = [];
+  chosenRange: Date[] = [];
 
   set minDate(value: Date) {
     this._effects.setMinDate(value);
@@ -74,7 +75,9 @@ export abstract class BsDatepickerAbstractComponent {
 
   yearSelectHandler(event: CalendarCellViewModel): void {}
 
-  /* tslint:disable-next-line: no-any */
+  setRangeOnCalendar(dates: BsCustomDates): void {}
+
+    /* tslint:disable-next-line: no-any */
   _stopPropagation(event: any): void {
     event.stopPropagation();
   }

src/datepicker/themes/bs/bs-daterangepicker-container.component.ts

@@ -150,7 +150,7 @@ export class BsDaterangepickerContainerComponent extends BsDatepickerAbstractCom
     this._effects.destroy();
   }
 
-  setRangeOnCalendar(dates: BsCustomDates) {
+  setRangeOnCalendar(dates: BsCustomDates): void {
     this._rangeStack = (dates === null) ? [] : (dates.value instanceof Date ? [dates.value] : dates.value);
     this._store.dispatch(this._actions.selectRange(this._rangeStack));
   }