birth :: [Records] -> Maybe Birth
birth rs = S.headMay $ do
    (typed -> Just (Bi b@(Birth _ _))) <- childrenBi rs
    return b
birth :: [Records] -> Maybe Birth
birth rs = S.headMay $ do
    (typed -> Just (Bi b@(Birth _ _))) <- childrenBi rs
    return b
birth rs = S.headMay $ do
    (typed -> Just (Bi b@(Birth _ _))) <- childrenBi rs
    return b