syntax_data: {"ast_node_type":"other","tokens":[{"end":26,"kind":"keyword","start":0,"text":".map_err(|e|"}]}
source_snippet:             .map_err(|e| {
context_before:             .eq(DefineOpaqueTypes::No, placeholder_obligation_trait_ref, impl_trait_ref)
context_after:                 debug!("match_impl: failed eq_trait_refs due to `{}`", e.to_string(self.tcx()))