promql/functions.go
func funcCountOverTime(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return aggrOverTime(vals, enh, func(values []Point) float64 {
		return float64(len(values))
	})
}
func funcCountOverTime(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return aggrOverTime(vals, enh, func(values []Point) float64 {
		return float64(len(values))
	})
}
// === count_over_time(Matrix ValueTypeMatrix) Vector ===