'L{Flags.iterconstants} returns an iterator over all of the constants
defined in the class, in the order they were defined.'

def test_iterconstants(self):

    constants = list(self.FXF.iterconstants())
    self.assertEqual([self.FXF.READ, self.FXF.WRITE, self.FXF.APPEND, self.FXF.EXCLUSIVE, self.FXF.TEXT], constants)
