code: func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
  	metric, err := v.metricVec.getMetricWith(labels)
  	if metric != nil {
  		return metric.(Gauge), err
  	}
  	return nil, err
  }
docs: // GetMetricWith returns the Gauge for the given Labels map (the label names
  // must match those of the VariableLabels in Desc). If that label map is
  // accessed for the first time, a new Gauge is created. Implications of
  // creating a Gauge without using it and keeping the Gauge for later use are
  // the same as for GetMetricWithLabelValues.
  //
  // An error is returned if the number and names of the Labels are inconsistent
  // with those of the VariableLabels in Desc (minus any curried labels).
  //
  // This method is used for the same purpose as
  // GetMetricWithLabelValues(...string). See there for pros and cons of the two
  // methods.