syntax_data: {"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":".eq(DefineOpaqueTypes::Yes,"}]}
source_snippet:                     .eq(DefineOpaqueTypes::Yes, b, a)
context_before:                     .at(&obligation.cause, obligation.param_env)
context_after:                     .map_err(|_| SelectionError::Unimplemented)?;