def create_platform_network(enode, category, config):
    """
    Create a Topology managed network with given configuration (netns, prefix).

    :param enode: The platform (a.k.a "engine") node to configure.
    :param str category: Name of the panel category.
    :param dict config: Configuration for the network. A dictionary like:

     ::

        {
            'netns': 'mynetns',
            'managed_by': 'platform',
            'prefix': ''
        }

     This dictionary is taken from the ``node._get_network_config()`` result.
    """
    netns = config.get('netns', None)
    if netns is None:
        return
    enode._docker_exec('ip netns add {}'.format(netns))
    enode._docker_exec('ip netns exec {} ip link set dev lo up'.format(netns))
