def METHOD_NAME(self):
    for tag in ["bpm"]:
        self.mp4[tag] = "3"
        self.failUnlessEqual(self.mp4[tag], ["3"])
        self.mp4.save()
        mp4 = EasyMP4(self.filename)
        self.failUnlessEqual(mp4[tag], ["3"])
        del mp4[tag]
        self.failIf(tag in mp4)
        self.failUnlessRaises(KeyError, mp4.__delitem__, tag)
        self.failUnlessRaises(
            ValueError, self.mp4.__setitem__, tag, "hello")