@Nullable
  @Override
  public PyType getReferenceExpressionType(@NotNull PyReferenceExpression referenceExpression, @NotNull TypeEvalContext context) {
    if (!referenceExpression.isQualified()) {
      final String name = referenceExpression.getReferencedName();
      if (PyNames.NONE.equals(name)) {
        return PyNoneType.INSTANCE;
      }
      else if (PyNames.FALSE.equals(name) || PyNames.TRUE.equals(name)) {
        return PyBuiltinCache.getInstance(referenceExpression).getBoolType();
      }
    }

    return null;
  }
@Nullable
  @Override
  public PyType getReferenceExpressionType(@NotNull PyReferenceExpression referenceExpression, @NotNull TypeEvalContext context)