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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 reserve_position(fp, fmt='I'):
 """ Reserves the current position for write. Use with `write_position`. :param fp: file-like object :param fmt: format of the reserved position :return: the position """

    position = fp.tell()
    fp.seek(struct.calcsize(str('>' + fmt)), 1)
    return position