ert2 :: TypeRep -> TypeRep -> a -> HashMap TypeRep (HashMap TypeRep a) -> HashMap TypeRep (HashMap TypeRep a)
insert2 x y v = M.insertWith (const $ M.insert y v) x (M.singleton y v)
{-
insert2 :: TypeRep -> TypeRep -> a -> HashMap TypeRep (HashMap TypeRep a) -> HashMap TypeRep (HashMap TypeRep a)
insert2 x y v = M.insertWith (const $ M.insert y v) x (M.singleton y v)
insert2 x y v = M.insertWith (const $ M.insert y v) x (M.singleton y v)