performance/performance.go
func (p *GetMetricsParams) Do(ctx context.Context) (metrics []*Metric, err error) {
	// execute
	var res GetMetricsReturns
	err = cdp.Execute(ctx, CommandGetMetrics, nil, &res)
	if err != nil {
		return nil, err
	}

	return res.Metrics, nil
}
func (p *GetMetricsParams) Do(ctx context.Context) (metrics []*Metric, err error) {
	// execute
	var res GetMetricsReturns
	err = cdp.Execute(ctx, CommandGetMetrics, nil, &res)
	if err != nil {
		return nil, err
	}

	return res.Metrics, nil
}
// Do executes Performance.getMetrics against the provided context.
//
// returns:
//   metrics - Current values for run-time metrics.