syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"ByRef::Yes(if"}]}
source_snippet:             ByRef::Yes(if mutable { Mutability::Mut } else { Mutability::Not })
context_before:             let mutable = self.pat_has_ref_mut_binding(inner);
context_after:         }