'Return row values in the given range.'

def range(self, lower, upper, bounds=(True, True)):

    if (not bounds[0]):
        lower = Epsilon(lower)
    if bounds[1]:
        upper = Epsilon(upper)
    l = [v for v in self.data.value_slice(lower, upper)]
    if self.unique:
        return l
    return [x for sublist in l for x in sublist]
