syntax_data: {"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // require `#[derive(PartialEq)]`
context_before:     let ocx = ObligationCtxt::new(infcx);
context_after:     let structural_peq_def_id = infcx.tcx.require_lang_item(LangItem::StructuralPeq, cause.span);