syntax_data: {"ast_node_type":"other","tokens":[{"end":59,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // replaced with fresh types starting from index 0.
context_before:         // this is because we want the unbound variables to be
context_after:         let cache_fresh_trait_pred = self.infcx.freshen(stack.obligation.predicate);