syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"UnsafeBinder(UnsafeBinderInner<I>),"}]}
source_snippet:     UnsafeBinder(UnsafeBinderInner<I>),
context_before:     /// a lifetime is literally inexpressible, such as self-referential types.