/// <summary>
/// Return a collection of the keys contained in this cache for
/// entries that satisfy the criteria expressed by the filter.
/// </summary>
/// <param name="filter">
/// The <see cref="IFilter"/> object representing the criteria that
/// the entries of this cache should satisfy.
/// </param>
/// <returns>
/// A collection of keys for entries that satisfy the specified
/// criteria.
/// </returns>
public virtual object[] GetKeys(IFilter filter)
{
return(NamedCache.GetKeys(filter));
}