unsafeFreezeNonEmptyBuffer :: Buffer -> Maybe S.ByteString
unsafeFreezeNonEmptyBuffer buf
  | sliceSize buf <= 0 = Nothing
  | otherwise          = Just $ unsafeFreezeBuffer buf
unsafeFreezeNonEmptyBuffer :: Buffer -> Maybe S.ByteString
unsafeFreezeNonEmptyBuffer buf
  | sliceSize buf <= 0 = Nothing
  | otherwise          = Just $ unsafeFreezeBuffer buf
unsafeFreezeNonEmptyBuffer buf
  | sliceSize buf <= 0 = Nothing
  | otherwise          = Just $ unsafeFreezeBuffer buf