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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 disable_openssh_rdns(distribution):
 """ Set 'UseDNS no' in openssh config to disable rDNS lookups On each request for a new channel openssh defaults to an rDNS lookup on the client IP. This can be slow, if it fails for instance, adding 10s of overhead to every request for a new channel (not connection). This can add a lot of time to a process that opens lots of channels (e.g. running several commands via fabric.) This function will disable rDNS lookups in the openssh config and reload ssh to adjust the running instance. :param bytes distribution: the name of the distribution running on the node. """

    log_green('Disabling openssh reverse dns lookups')
    openssh_config_file = '/etc/ssh/sshd_config'
    dns_config = 'UseDNS no'
    if not file_contains(openssh_config_file, dns_config, use_sudo=True):
        file_append(openssh_config_file, dns_config, use_sudo=True)
        service_name = 'sshd'
        if 'ubuntu' in distribution:
            service_name = 'ssh'
        sudo('service {} reload'.format(service_name))