syntax_data: {"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"rustc_serialize::Decodable::decode(decoder),"}]}
source_snippet:             rustc_serialize::Decodable::decode(decoder),
context_before:         UnsafeBinderInner(ty::Binder::bind_with_vars(
context_after:             bound_vars,