query.go
func (iter Enumerator) ParallelSelect(operation Transform) Enumerator {
	if cpus := runtime.NumCPU(); cpus != 1 {
		intermediate := iter.splitN(operation, uint(cpus))
		return intermediate[0].Merge(intermediate[1:]...)
	}
	return iter
}
func (iter Enumerator) ParallelSelect(operation Transform) Enumerator {
	if cpus := runtime.NumCPU(); cpus != 1 {
		intermediate := iter.splitN(operation, uint(cpus))
		return intermediate[0].Merge(intermediate[1:]...)
	}
	return iter
}
// ParallelSelect will execute a Transform across all logical CPUs available to the current process.