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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 sodium_increment(inp):
 """ Increment the value of a byte-sequence interpreted as the little-endian representation of a unsigned big integer. :param inp: input bytes buffer :type inp: bytes :return: a byte-sequence representing, as a little-endian unsigned big integer, the value ``to_int(inp)`` incremented by one. :rtype: bytes """

    ensure(isinstance(inp, bytes),
           raising=exc.TypeError)

    ln = len(inp)
    buf = ffi.new("unsigned char []", ln)

    ffi.memmove(buf, inp, ln)

    lib.sodium_increment(buf, ln)

    return ffi.buffer(buf, ln)[:]