syntax_data: {"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // double-check there even *is* a semantic `PartialEq` to dispatch to.
context_before:     let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
context_after:     //