syntax_data: {"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let vtable_coroutine = self.confirm_coroutine_candidate(obligation)?;
context_before:             CoroutineCandidate => {
context_after:                 ImplSource::Builtin(BuiltinImplSource::Misc, vtable_coroutine)