syntax_data: {"ast_node_type":"other","tokens":[{"end":22,"kind":"keyword","start":0,"text":"tcx:"}]}
source_snippet:     tcx: TyCtxt<'tcx>,
context_before:     push_cuta: impl FnMut(&Box<CanonicalUserType<'tcx>>) -> Option<UserTypeAnnotationIndex>,
context_after: ) -> ConstOperand<'tcx> {