code: func (m *CirconusMetrics) FlushMetrics() *Metrics {
  	m.flushmu.Lock()
  	if m.flushing {
  		m.flushmu.Unlock()
  		return &Metrics{}
  	}
  
  	m.flushing = true
  	m.flushmu.Unlock()
  
  	_, output := m.packageMetrics()
  
  	m.flushmu.Lock()
  	m.flushing = false
  	m.flushmu.Unlock()
  
  	return &output
  }
docs: // FlushMetrics flushes current metrics to a structure and returns it (does NOT send to Circonus)