syntax_data: {"ast_node_type":"variable","tokens":[{"end":34,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let def = tcx.adt_def(def_id);
context_before: fn unsizing_params_for_adt<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> DenseBitSet<u32> {
context_after:     let num_params = tcx.generics_of(def_id).count();