public ColorBalanceChannel (string label, int min, int max) : this () {
  unsafe {
    int* raw_ptr = (int*) ( ( (byte*) Handle) + max_value_offset);
    *raw_ptr = max;
  }
  unsafe {
    IntPtr* raw_ptr = (IntPtr*) ( ( (byte*) Handle) + label_offset);
    *raw_ptr = GLib.Marshaller.StringToPtrGStrdup (label);
  }
  unsafe {
    int* raw_ptr = (int*) ( ( (byte*) Handle) + min_value_offset);
    *raw_ptr = min;
  }
}