docs: function (layerGroup) {
  		var otherMcgLayerSupportGroup = layerGroup._proxyMcgLayerSupportGroup;
  
  		// If it is not yet in this group, remove it from previous group
  		// or from map.
  		if (otherMcgLayerSupportGroup) {
  			if (otherMcgLayerSupportGroup === this) {
  				return;
  			}
  			// Remove from previous Layer Support group first.
  			// It will also be removed from map with child layers.
  			otherMcgLayerSupportGroup.checkOut(layerGroup);
  		} else {
  			this._removeFromOwnMap(layerGroup);
  		}
  
  		layerGroup._proxyMcgLayerSupportGroup = this;
  		layerGroup._originalAddLayer =
  			layerGroup._originalAddLayer || layerGroup.addLayer;
  		layerGroup._originalRemoveLayer =
  			layerGroup._originalRemoveLayer || layerGroup.removeLayer;
  		layerGroup._originalOnAdd =
  				layerGroup._originalOnAdd || layerGroup.onAdd;
  		layerGroup._originalOnRemove =
  				layerGroup._originalOnRemove || layerGroup.onRemove;
  		L.extend(layerGroup, _proxyLayerGroup);
  	}