syntax_data: {"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // 3) ['x] + ['b] -> ['x, 'b]
context_before:         let new = EarlyBinder::bind(shifted_pred).instantiate(tcx, trait_ref.skip_binder().args);
context_after:         let bound_vars =