syntax_data: {"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"ty::Binder::dummy(ty::PredicateKind::DynCompatible(principal)),"}]}
source_snippet:                         ty::Binder::dummy(ty::PredicateKind::DynCompatible(principal)),
context_before:                         self.param_env,
context_after:                     ));