datadog/reporter.go
func (r *Reporter) Metric(name string, tags []string, v float32) {
	r.metrics = append(r.metrics, Metric{
		Name:   name,
		Points: [][2]interface{}{[2]interface{}{r.timestamp, v}},
		Tags:   tags,
		Host:   r.Hostname,
	})
}
func (r *Reporter) Metric(name string, tags []string, v float32) {
	r.metrics = append(r.metrics, Metric{
		Name:   name,
		Points: [][2]interface{}{[2]interface{}{r.timestamp, v}},
		Tags:   tags,
		Host:   r.Hostname,
	})
}
// Metric appends a new metric to the reporter. The value v must be either an
// int64 or float64, otherwise an error is returned