testExtendEnd :: (Int, Array U DIM1 Double, Array U DIM1 Double)
              -> Assertion
testExtendEnd (ln, sig, expected) =
    expected @=~? forceS (extendEnd ln sig)
testExtendEnd :: (Int, Array U DIM1 Double, Array U DIM1 Double)
              -> Assertion
testExtendEnd (ln, sig, expected) =
    expected @=~? forceS (extendEnd ln sig)
testExtendEnd (ln, sig, expected) =
    expected @=~? forceS (extendEnd ln sig)