def for_actor(id: nil, guid: nil, default_properties: {})
      ActorControl.new(self, id: id, guid: guid, default_properties: default_properties)
    end
def for_actor(id: nil, guid: nil, default_properties: {})
      ActorControl.new(self, id: id, guid: guid, default_properties: default_properties)
    end
Creates a new determinator instance which assumes the actor id, guid and properties given
 are always specified. This is useful for within a before filter in a webserver, for example,
 so that the determinator instance made available has the logged-in user's credentials prefilled.

 @param :id [#to_s] The ID of the actor being specified
 @param :guid [#to_s] The Anonymous ID of the actor being specified
 @param :default_properties [Hash<Symbol,String>] The default properties for the determinator being created
 @return [ActorControl] A helper object removing the need to know id and guid everywhere