adsk-forge-SelectionMonitor-step10

load() {
    this.onBuildingContextMenuItem = this.onBuildingContextMenuItem.bind( this );

    //...

    this.onBuildingContextMenuItem = this.onBuildingContextMenuItem.bind( this );

    this.viewer.registerContextMenuCallback(
        'Autodesk.ADN.ColorMenu',
    this.onBuildingContextMenuItem
    );
    return true;
}