def test_highNum():
assert arb2rom(3000) == 'MMM'
def test_lowNum():
assert arb2rom(2) == 'II'
def test_orange():
assert arb2rom(400000) == ''
def test_string():
assert arb2rom('hello') == ''
def test_decimal():
assert arb2rom(7.9) == ''
def test_avgNum():
assert arb2rom(50) == 'L'