{"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"let"}]}
    let ty = sema.type_of_expr(&ast::Expr::ClosureExpr(descended_closure.clone()))?.adjusted();
    let descended_closure = sema.descend_node_into_attributes(closure.clone()).pop()?;
    let callable = ty.as_callable(sema.db)?;