syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"self.rust_2024_migration.as_mut().and_then(|s|"}]}
source_snippet:                     self.rust_2024_migration.as_mut().and_then(|s| s.visit_explicit_deref());
context_before:                 let opt_old_mode_span =
context_after:                 let subpattern = self.lower_pattern(subpattern);