syntax_data: {"ast_node_type":"variable","tokens":[{"end":41,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:         if let Some(&user_ty) = user_ty {
context_before:         // type, add an ascription node (e.g. `<Foo<'a> as MyTrait>::CONST`).
context_after:             let annotation = CanonicalUserTypeAnnotation {