syntax_data: {"ast_node_type":"impl","tokens":[{"end":56,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// A trait goal was satisfied by an impl candidate.
context_before:     NestedProbe(Probe<I>),
context_after:     RecordImplArgs { impl_args: CanonicalState<I, I::GenericArgs> },