syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // within the signature, such as in function pointer or `dyn Trait` args.
context_before:         // binders anonymized. We call `erase_regions` once again to anonymize any binders
context_after:         let caller_sig = self.tcx.erase_regions(caller_sig);