//copies the items in the dictionary into the array
public void CopyTo(KeyValuePair <TKey, HashSet <TValue> >[] array, int arrayIndex)
{
if (array == null)
{
throw new ArgumentNullException();
}
if (arrayIndex < 0 || arrayIndex > array.Count())
{
throw new ArgumentOutOfRangeException();
}
if ((array.Count() - arrayIndex) < MultiDictionary.Count())
{
throw new ArgumentException();
}
foreach (var pair in MultiDictionary)
{
array[arrayIndex] = pair;
++arrayIndex;
}
}