private void initializeInCall() {
    if (mCallCardFragment == null) {
      mCallCardFragment =
          (CallCardFragment) getFragmentManager().findFragmentById(R.id.callCardFragment);
    }

    mChildFragmentManager = mCallCardFragment.getChildFragmentManager();

    if (mCallButtonFragment == null) {
      mCallButtonFragment =
          (CallButtonFragment) mChildFragmentManager.findFragmentById(R.id.callButtonFragment);
      mCallButtonFragment.getView().setVisibility(View.INVISIBLE);
    }

    if (mAnswerFragment == null) {
      mAnswerFragment =
          (AnswerFragment) mChildFragmentManager.findFragmentById(R.id.answerFragment);
    }

    if (mConferenceManagerFragment == null) {
      mConferenceManagerFragment =
          (ConferenceManagerFragment)
              getFragmentManager().findFragmentById(R.id.conferenceManagerFragment);
      mConferenceManagerFragment.getView().setVisibility(View.INVISIBLE);
    }
  }