syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"I::Ty:"}]}
source_snippet:     I::Ty: TypeVisitable<I> + rustc_serialize::Decodable<D>,
context_before: where
context_after:     I::BoundVarKinds: rustc_serialize::Decodable<D>,