syntax_data: {"ast_node_type":"other","tokens":[{"end":22,"kind":"keyword","start":0,"text":"tcx:"}]}
source_snippet:     tcx: TyCtxt<'tcx>,
context_before: pub fn expand_trait_aliases<'tcx>(
context_after:     clauses: impl IntoIterator<Item = (ty::Clause<'tcx>, Span)>,