syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"None"}]}
source_snippet:             None => cg.symbol_mangling_version = Some(SymbolManglingVersion::V0),
context_before:         match cg.symbol_mangling_version {
context_after:             Some(SymbolManglingVersion::Legacy) => {