syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"(&ty::Dynamic(data_a,"}]}
source_snippet:             (&ty::Dynamic(data_a, r_a, dyn_a), &ty::Dynamic(data_b, r_b, dyn_b))
context_before:             // Trait+Kx+'a -> Trait+Ky+'b (auto traits and lifetime subtyping).
context_after:                 if dyn_a == dyn_b =>