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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_reversed_unification_program(angles, control_indices, target, controls, mode):
 """ Gets the Program representing the reversed circuit for the decomposition of the uniformly controlled rotations in a unification step. If :math:`n` is the number of controls, the indices within control indices must range from 1 to :math:`n`, inclusive. The length of control_indices and the length of angles must both be :math:`2^n`. :param list angles: The angles of rotation in the the decomposition, in order from left to right :param list control_indices: a list of positions for the controls of the CNOTs used when decomposing uniformly controlled rotations; see get_cnot_control_positions for labelling conventions. :param int target: Index of the target of all rotations :param list controls: Index of the controls, in order from bottom to top. :param str mode: The unification mode. Is either 'phase', corresponding to controlled RZ rotations, or 'magnitude', corresponding to controlled RY rotations. :return: The reversed circuit of this unification step. :rtype: Program """

    if mode == 'phase':
        gate = RZ
    elif mode == 'magnitude':
        gate = RY
    else:
        raise ValueError("mode must be \'phase\' or \'magnitude\'")

    reversed_gates = []

    for j in range(len(angles)):
        if angles[j] != 0:
            # angle is negated in conjugated/reversed circuit
            reversed_gates.append(gate(-angles[j], target))
        if len(controls) > 0:
            reversed_gates.append(CNOT(controls[control_indices[j] - 1],
                                       target))

    return Program().inst(reversed_gates[::-1])