Method _focusChanged

src/material/tabs/tab-group.ts:474–477

(index: number)

  }

  _focusChanged(index: number) {
    this._lastFocusedTabIndex = index;
    this.focusChange.emit(this._createChangeEvent(index));
  }

  private _createChangeEvent(index: number): MatTabChangeEvent {
    const event = new MatTabChangeEvent();