@Override
  public void visitPyReferenceExpression(final @NotNull PyReferenceExpression node) {
    if (myPositive && (isIfReferenceStatement(node) || isIfReferenceConditionalStatement(node) || isIfNotReferenceStatement(node))) {
      // we could not suggest `None` because it could be a reference to an empty collection
      // so we could push only non-`None` assertions
      pushAssertion(node, !myPositive, false, context -> PyNoneType.INSTANCE, null);
      return;
    }

    super.visitPyReferenceExpression(node);
  }
@Override
  public void visitPyReferenceExpression(final @NotNull PyReferenceExpression node)