syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":"impl_def_id={:?},"}]}
source_snippet:                  impl_def_id={:?}, trait_def_id={:?}",
context_before:                 "insert: inserting dummy node for erroneous TraitRef {:?}, \
context_after:                 trait_ref, impl_def_id, trait_def_id