{"ast_node_type":"variable","tokens":[{"end":61,"kind":"keyword","start":0,"text":"let"}]}
        let mut expr_finder = FindExprBySpan::new(span, tcx);
        let body_id = tcx.hir_node(self.mir_hir_id()).body_id()?;
        expr_finder.visit_expr(tcx.hir_body(body_id).value);