promql/functions.go
func funcRate(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return extrapolatedRate(vals, args, enh, true, true)
}
func funcRate(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return extrapolatedRate(vals, args, enh, true, true)
}
// === rate(node ValueTypeMatrix) Vector ===