{"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"//"}]}
                    // the Fn or FnMut trait, it should be one of those.
                    // Check for &self vs &mut self in the method signature. Since this is either
                    let ty::Ref(_, _, mutbl) = method.sig.inputs()[0].kind() else {