syntax_data: {"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":".map(|(i,"}]}
source_snippet:                 .map(|(i, variant_def)| {
context_before:                 .iter_enumerated()
context_after:                     let fields: Vec<_> = variant_def.fields.iter().map(|f| f.name).collect();