syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"ExprKind::ValueTypeAscription"}]}
source_snippet:             ExprKind::ValueTypeAscription { source, ref user_ty, user_ty_span } => {
context_before:             }
context_after:                 let source_expr = &this.thir[source];