syntax_data: {"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// be normalized, so they are grouped conceptually.
context_before:     /// All of these types are represented as pairs of def-id and args, and can
context_after:     Alias(AliasTyKind, AliasTy<I>),