public void Save(TextWriter writer)
{
var kvp = new KeyValuePairs();
kvp.Comment = "Campaign data";
kvp.Set("title", Title);
kvp.SetStringArray("levels", Levels.ToArray());
kvp.SetIntegerArray("checkpoints", Checkpoints.ToArray());
kvp.Set("id", m_id);
kvp.Set("initial_levels_unlocked", m_initialLevelsUnlocked);
if (m_hidden)
{
kvp.Set("hidden", m_hidden);
}
kvp.Save(writer);
}