docs: def port_add(br, port, may_exist=False, internal=False):
      '''
      Creates on bridge a new port named port.
  
      Returns:
          True on success, else False.
  
      Args:
          br: A string - bridge name
          port: A string - port name
          may_exist: Bool, if False - attempting to create a port that exists returns False.
          internal: A boolean to create an internal interface if one does not exist.
  
      .. versionadded:: 2016.3.0
  
      CLI Example:
      .. code-block:: bash
  
          salt '*' openvswitch.port_add br0 8080
      '''
      param_may_exist = _param_may_exist(may_exist)
      cmd = 'ovs-vsctl {2}add-port {0} {1}'.format(br, port, param_may_exist)
      if internal:
          cmd += ' -- set interface {0} type=internal'.format(port)
      result = __salt__['cmd.run_all'](cmd)
      retcode = result['retcode']
      return _retcode_to_bool(retcode)