// KindUint64 indicates that the type of the Value is a uint64.
	KindUint64

	// KindFloat64 indicates that the type of the Value is a float64.
	KindFloat64

	// KindFloat64Histogram indicates that the type of the Value is a *Float64Histogram.
	KindFloat64Histogram
)

// Value represents a metric value returned by the runtime.
type Value struct {
	kind    ValueKind
	scalar  uint64         // contains scalar values for scalar Kinds.