code: func (p *PrometheusReporter) ReportSummary(metric string, labels map[string]string, value float64) error {
  	sum := p.summaryReportersMap[metric]
  	if sum != nil {
  		labels = p.ensureLabels(labels)
  		sum.With(labels).Observe(value)
  		return nil
  	}
  	return constants.ErrMetricNotKnown
  }
docs: // ReportSummary reports a summary metric