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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 decode(decoder, data, length, frame_size, decode_fec, channels=2):
 """Decode an Opus frame Unlike the `opus_decode` function , this function takes an additional parameter `channels`, which indicates the number of channels in the frame """


    pcm_size = frame_size * channels * ctypes.sizeof(ctypes.c_int16)
    pcm = (ctypes.c_int16 * pcm_size)()
    pcm_pointer = ctypes.cast(pcm, c_int16_pointer)

    # Converting from a boolean to int
    decode_fec = int(bool(decode_fec))

    result = _decode(decoder, data, length, pcm_pointer, frame_size, decode_fec)
    if result < 0:
        raise OpusError(result)

    return array.array('h', pcm).tostring()