syntax_data: {"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"Self"}]}
source_snippet:         Self { def_id: trait_def_id, args, _use_existential_trait_ref_new_instead: () }
context_before:         interner.debug_assert_existential_args_compatible(trait_def_id, args);
context_after:     }