def myassert(cond : => Boolean) = {
  try {
    assert(cond)
  } catch { 
    case _ : Throwable => System.exit(1)
  }
}

myassert(get_delta(None, None) == None)
myassert(get_delta(Some(50.0), None) == None)
myassert(get_delta(None, Some(100.0)) == None)
myassert(get_delta(Some(50.0), Some(100.0)) == Some(1.0))