def METHOD_NAME(self):
    """Verify that s390_sanitize_dev_input works as expected"""
    dev = "1234"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), '0.0.' + dev)
    dev = "123456"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), '0.0.' + dev)
    # the device number is padded on the left with 0s up to 4 digits
    dev = "123.abc"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), "0.0.0abc")
    dev = "abc"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), "0.0.0abc")
    dev = ".abc"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), "0.0.0abc")
    # a complete number is unchanged
    dev = "0.0.abcd"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), dev)
    # a too long number doesn't mean a crash no matter if it makes sense
    dev = "0.0.abcdefgh"
    self.assertEqual(BlockDev.s390_sanitize_dev_input(dev), dev)