code: func AddSample(key []string, val float32) {
  	normalizeKeys(key)
  
  	GetMetrics().AddSample(key, val)
  }
docs: // AddSample adds a sample to an aggregated metric
  // reporting count, min, max, mean, and std deviation
  // Usage:
  //     AddSample([]string{"my","namespace","key"}, 15.0)