{"ast_node_type":"other","tokens":[{"end":58,"kind":"keyword","start":0,"text":"Union(Ident,"}]}
    Union(Ident, &'hir Generics<'hir>, VariantData<'hir>),
    /// A union definition, e.g., `union Foo<A, B> {x: A, y: B}`.
    /// A trait definition.