def test_xxx(self): self.assertEquals(find_subtractive_combinations("XXX"), ())
def test_mmmcccxxxviii(self): self.assertEquals(find_subtractive_combinations("MMMCCCXXXVIII"), ())
def test_cmxliv(self): self.assertEquals(find_subtractive_combinations("CMXLIV"), ( ("CM", 0), ("XL", 2), ("IV", 4), ))
def test_i(self): self.assertEquals(find_subtractive_combinations("I"), ())
def test_mcm(self): self.assertEquals(find_subtractive_combinations("MCM"), (("CM", 1), ))
def test_ccxciv(self): self.assertEquals(find_subtractive_combinations("CCXCIV"), ( ("XC", 2), ("IV", 4), ))
def test_cxc(self): self.assertEquals(find_subtractive_combinations("CXC"), (("XC", 1), ))
def test_xix(self): self.assertEquals(find_subtractive_combinations("XIX"), (("IX", 1), ))
def test_cd(self): self.assertEquals(find_subtractive_combinations("CD"), (("CD", 0), ))
def test_xl(self): self.assertEquals(find_subtractive_combinations("XL"), (("XL", 0), ))
def test_iv(self): self.assertEquals(find_subtractive_combinations("IV"), (("IV", 0), ))