syntax_data: {"ast_node_type":"other","tokens":[{"end":27,"kind":"keyword","start":0,"text":"item_def_id:"}]}
source_snippet:         item_def_id: DefId,
context_before:         tcx: TyCtxt<'tcx>,
context_after:         args: impl IntoIterator<Item: Into<GenericArg<'tcx>>>,