syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"Some(trait_def_id)"}]}
source_snippet:                 Some(trait_def_id) => {
context_before:             let trait_args = match tcx.trait_of_assoc(def_id.to_def_id()) {
context_after:                     let trait_args_count = tcx.generics_of(trait_def_id).count();