syntax_data: {"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let trait_assoc_generics = tcx.generics_of(trait_assoc_def_id);
context_before:     impl_assoc_ty.generics_of({
context_after:         let trait_assoc_parent_count = trait_assoc_generics.parent_count;