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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_transport(host, username, key):
 """ Create a transport object :param host: the hostname to connect to :type host: str :param username: SSH username :type username: str :param key: key object used for authentication :type key: paramiko.RSAKey :return: a transport object :rtype: paramiko.Transport """


    if host == shakedown.master_ip():
        transport = paramiko.Transport(host)
    else:
        transport_master = paramiko.Transport(shakedown.master_ip())
        transport_master = start_transport(transport_master, username, key)

        if not transport_master.is_authenticated():
            print("error: unable to authenticate {}@{} with key {}".format(username, shakedown.master_ip(), key))
            return False

        try:
            channel = transport_master.open_channel('direct-tcpip', (host, 22), ('127.0.0.1', 0))
        except paramiko.SSHException:
            print("error: unable to connect to {}".format(host))
            return False

        transport = paramiko.Transport(channel)

    return transport