syntax_data: {"ast_node_type":"other","tokens":[{"end":28,"kind":"keyword","start":0,"text":"user_ty,"}]}
source_snippet:                     user_ty,
context_before:                     Ty::new_fn_def(self.tcx, def_id, self.typeck_results.node_args(expr.hir_id)),
context_after:                 )