syntax_data: {"ast_node_type":"other","tokens":[{"end":55,"kind":"keyword","start":0,"text":"match"}]}
source_snippet:             match (self.contains(i), old.contains(i)) {
context_before:         for i in (0..size).map(T::new) {
context_after:                 (true, false) => set_in_self.insert(i),