func Buffer[T any](seq iter.Seq[T], size int) iter.Seq[[]T] {
      return func(yield func([]T) bool) {
            buffer := make([]T, 0, size)

            seq(func(v T) bool {
                  buffer = append(buffer, v)
                  if len(buffer) < size {
                      return true  // keep pulling
                  }
                  // Buffer full, yield it
                  result := buffer
                  buffer = make([]T, 0, size)  // allocate new buffer
                  return yield(result)  // false = stop, true = continue
            })

            // Yield remaining partial buffer
            if len(buffer) > 0 {
                yield(buffer)
            }
      }
}