code: func NewFloat(name string, description string, metadata *types.MetricMetadata, fields ...field.Field) Float {
  	if metadata == nil {
  		metadata = &types.MetricMetadata{}
  	}
  	m := &floatMetric{metric{
  		MetricInfo: types.MetricInfo{
  			Name:        name,
  			Description: description,
  			Fields:      fields,
  			ValueType:   types.NonCumulativeFloatType,
  		},
  		MetricMetadata: *metadata,
  	}}
  	registry.Add(m)
  	return m
  }
docs: // NewFloat returns a new non-cumulative floating-point gauge metric.