code: function(listener, listeners_by_event) {
  
  		var list = listeners_by_event[listener.event_name],
  			index;
  
  		if (list) {
  			index = list.indexOf(listener);
  			if (index != -1) {
  				list.splice(index, 1);
  				if (list.length == 0) {
  					listeners_by_event[listener.event_name] = null;
  				}
  			}
  		}
  
  	}
docs: Perform removal of the listener structure
  @param {_tListener} listener Structure, which was returned by {@link Lava.mixin.Observable#on} method
  @param {Object.<string, Array.<_tListener>>} listeners_by_event {@link Lava.mixin.Observable#_listeners} or {@link Lava.mixin.Properties#_property_listeners}