{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":".generics_of(parent_def_id)"}]}
                                    .generics_of(parent_def_id)
                                let defaulted_param_idx = tcx
                                    .param_def_id_to_index[&defaulted_param_def_id.to_def_id()];