{"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"if"}]}
        if let ExprKind::Call(path, [arg]) = expr.kind
    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
            && let ExprKind::Path(ref qpath) = path.kind