syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"(MaybeReachable::Reachable(x),"}]}
source_snippet:             (MaybeReachable::Reachable(x), MaybeReachable::Reachable(y)) => {
context_before:         match (&mut *self, source) {
context_after:                 x.clone_from(y);