syntax_data: {"ast_node_type":"other","tokens":[{"end":31,"kind":"keyword","start":0,"text":"impl_assoc_ty.generics_of({"}]}
source_snippet:     impl_assoc_ty.generics_of({
context_before:     // here, but it seems overkill.
context_after:         let trait_assoc_generics = tcx.generics_of(trait_assoc_def_id);