syntax_data: {"ast_node_type":"function","tokens":[{"end":73,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn insert_blindly(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId) {
context_before:     /// Insert an impl into this set of children without comparing to any existing impls.
context_after:         let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap().skip_binder();