private void getSemester() {
    Helper.getSemester(
        this,
        new SemesterCallback() {

          @Override
          public void onSuccess(List<SemesterModel> modelList, SemesterModel selectedModel) {
            super.onSuccess(modelList, selectedModel);
            mSemesterList = modelList;
            mSelectedModel = selectedModel;
            mYms = mSelectedModel.value;
            mPickYmsTextView.setText(mSelectedModel.text);
            getData(true);
          }

          @Override
          public void onFail(String errorMessage) {
            super.onFail(errorMessage);
            isRetry = true;
            setUpCourseTable();
          }
        });
  }