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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 _net_write(sock, data, expiration):
 """Write the specified data to the socket. A Timeout exception will be raised if the operation is not completed by the expiration time. """

    current = 0
    l = len(data)
    while current < l:
        _wait_for_writable(sock, expiration)
        current += sock.send(data[current:])