How to use the @terascope/teraslice-messaging.formatURL function in @terascope/teraslice-messaging

const {
            slicer_port: slicerPort,
            slicer_hostname: slicerHostname,
            performance_metrics: performanceMetrics
        } = executionContext.config;

        const config = context.sysconfig.teraslice;
        const networkLatencyBuffer = get(config, 'network_latency_buffer');
        const actionTimeout = get(config, 'action_timeout');
        const workerDisconnectTimeout = get(config, 'worker_disconnect_timeout');
        const slicerTimeout = get(config, 'slicer_timeout');
        const shutdownTimeout = get(config, 'shutdown_timeout');

        this.client = new ExecutionController.Client({
            executionControllerUrl: formatURL(slicerHostname, slicerPort),
            workerId,
            networkLatencyBuffer,
            workerDisconnectTimeout,
            // the connect timeout should be set to the same timeout that will
            // cause the execution fail if no Workers connect
            connectTimeout: slicerTimeout,
            actionTimeout,
            logger
        });

        this.slice = new Slice(context, executionContext);

        this.metrics = performanceMetrics
            ? new Metrics({
                logger
            })