syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"self.0.retain(|(k,"}]}
source_snippet:         self.0.retain(|(k, _)| prefixes.iter().any(|prefix| k.starts_with(prefix)));
context_before:     pub fn retain(&mut self, prefixes: &[&str]) {
context_after:     }