syntax_data: {"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"ExprKind::Adt(box"}]}
source_snippet:             ExprKind::Adt(box AdtExpr { adt_def, variant_index, args, fields, .. }) => {
context_before:             },
context_after:                 let is_union = adt_def.is_union();