_onContextLost(event)
    {
        event.preventDefault();
        this.onContextLost.dispatch(this);
    }
/**
     * Called when the underlying context is lost.
     *
     * @private
     * @param {WebGLContextEvent} event - The DOM event about the context being lost.
     */
Called when the underlying context is lost.
@private
@param {WebGLContextEvent} event - The DOM event about the context being lost.
Called when the underlying context is lost . @private @param { WebGLContextEvent } event - The DOM event about the context being lost .
_onContextLost(event)
    {
        event.preventDefault();
        this.onContextLost.dispatch(this);
    }
_onContextLost ( event ) { event . preventDefault ( ) ; this . onContextLost . dispatch ( this ) ; }
Called when the underlying context is lost.
Called when the underlying context is lost .