protected void UpdateNumObjectsOfCategory(string category, int delta)
{
if (null == category)
{
return;
}
if (!numObjectsByCat.ContainsKey(category))
{
numObjectsByCat.Add(category, 0);
}
numObjectsByCat[category] += delta;
if (parent != null)
{
parent.UpdateNumObjectsOfCategory(category, delta);
}
}