if err != nil {
		t.Fatal(err)
	}

	checkExpr := func(pos token.Pos, str string) (Object, error) {
		expr, err := parser.ParseExprFrom(fset, "eval", str, 0)
		if err != nil {
			return nil, err
		}

		info := &Info{
			Uses:       make(map[*ast.Ident]Object),
			Selections: make(map[*ast.SelectorExpr]*Selection),
		}
		if err := CheckExpr(fset, pkg, pos, expr, info); err != nil {