{"ast_node_type":"other","tokens":[{"end":46,"kind":"keyword","start":0,"text":"type"}]}
    type KeyType = (T1::KeyType, T2::KeyType);
impl<HCX, T1: ToStableHashKey<HCX>, T2: ToStableHashKey<HCX>> ToStableHashKey<HCX> for (T1, T2) {
    #[inline]