syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// or we hit a case where we just don't bother, e.g. `?x: Trait` goals.
context_before:     /// be a true ambiguity, i.e. there are multiple different answers,
context_after:     Ambiguity,