syntax_data: {"ast_node_type":"other","tokens":[{"end":25,"kind":"keyword","start":0,"text":"impl<'tcx>"}]}
source_snippet: impl<'tcx> At<'_, 'tcx> {
context_before: #[extension(pub trait StructurallyNormalizeExt<'tcx>)]
context_after:     fn structurally_normalize_ty<E: 'tcx>(