docs: def remove(self, *labelvalues):
          if not self._labelnames:
              raise ValueError('No label names were set when constructing %s' % self)
  
          """Remove the given labelset from the metric."""
          if len(labelvalues) != len(self._labelnames):
              raise ValueError('Incorrect label count (expected %d, got %s)' % (len(self._labelnames), labelvalues))
          labelvalues = tuple(unicode(l) for l in labelvalues)
          with self._lock:
              del self._metrics[labelvalues]