/// <returns>the Collection mapped to by key, never null, but may be empty.</returns>
public virtual TwoDimensionalCollectionValuedMap <K2, K3, V> GetTwoDimensionalCollectionValuedMap(K1 key1)
{
TwoDimensionalCollectionValuedMap <K2, K3, V> cvm = map[key1];
if (cvm == null)
{
cvm = new TwoDimensionalCollectionValuedMap <K2, K3, V>();
map[key1] = cvm;
}
return(cvm);
}
/// <summary>Adds the value to the Collection mapped to by the key.</summary>
public virtual void Add(K1 key1, K2 key2, K3 key3, V value)
{
TwoDimensionalCollectionValuedMap <K2, K3, V> cvm = GetTwoDimensionalCollectionValuedMap(key1);
cvm.Add(key2, key3, value);
}