text.go
func (m *CirconusMetrics) RemoveTextFunc(metric string) {
	m.tfm.Lock()
	defer m.tfm.Unlock()
	delete(m.textFuncs, metric)
}
func (m *CirconusMetrics) RemoveTextFunc(metric string) {
	m.tfm.Lock()
	defer m.tfm.Unlock()
	delete(m.textFuncs, metric)
}
// RemoveTextFunc a text metric function