@Nullable
  private static DfaValue getQualifierValue(DfaValueFactory factory, PsiExpression qualifierExpression) {
    DfaValue qualifierValue = getExpressionDfaValue(factory, qualifierExpression);
    if (qualifierValue == null) return null;
    PsiVariable constVar = qualifierValue.getDfType().getConstantOfType(PsiVariable.class);
    if (constVar != null) {
      return PlainDescriptor.createVariableValue(factory, constVar);
    }
    return qualifierValue;
  }
@Nullable
  private static DfaValue getQualifierValue(DfaValueFactory factory, PsiExpression qualifierExpression)