code: def overlay_gateway_activate(self, **kwargs):
          
  
          callback = kwargs.pop('callback', self._callback)
          get_config = kwargs.pop('get', False)
          if not get_config:
              gw_name = kwargs.pop('gw_name')
              overlay_gw = getattr(self._tunnels, 'overlay_gateway_activate')
              config = overlay_gw(name=gw_name)
  
          if get_config:
              overlay_gw = getattr(self._tunnels, 'overlay_gateway_activate')
              config = overlay_gw(name='')
              output = callback(config, handler='get_config')
              if output.data.find('.//{*}name') is not None:
                  if output.data.find('.//{*}activate') is not None:
                      return True
                  else:
                      return None
              else:
                  return None
  
          if kwargs.pop('delete', False):
              config.find('.//activate').set('operation', 'delete')
          return callback(config)
docs: Activates the Overlay Gateway Instance on VDX switches
  
          Args:
              gw_name: Name of Overlay Gateway
              get (bool): Get config instead of editing config. (True, False)
              delete (bool): True, delete the activate config. (True, False)
              callback (function): A function executed upon completion of the
                  method.  The only parameter passed to `callback` will be the
                  ``ElementTree`` `config`.
  
          Returns:
              Return value of `callback`.
  
          Raises:
              KeyError: if `gw_name` is not passed.
              ValueError: if `gw_name` is invalid.
  
          Examples:
              >>> import pynos.device
              >>> conn = ('10.24.39.211', '22')
              >>> auth = ('admin', 'password')
              >>> with pynos.device.Device(conn=conn, auth=auth) as dev:
              ...     output = dev.interface.overlay_gateway_activate(
              ...     gw_name='Leaf')
              ...     output = dev.interface.overlay_gateway_activate(
              ...     get=True)
              ...     output = dev.interface.overlay_gateway_activate(
              ...     gw_name='Leaf', delete=True)