/// <summary>Tests whether the specified <paramref name="key"/> starts with this Subspace's prefix, indicating that the Subspace logically contains <paramref name="key"/>.</summary>
 /// <param name="key">The key to be tested</param>
 /// <exception cref="System.ArgumentNullException">If <paramref name="key"/> is null</exception>
 public static bool Contains <TKey>(this FdbSubspace subspace, [NotNull] TKey key)
     where TKey : IFdbKey
 {
     if (key == null)
     {
         throw new ArgumentNullException("key");
     }
     return(subspace.Contains(key.ToFoundationDbKey()));
 }
 /// <summary>Test if a key is contained by this database instance.</summary>
 /// <param name="key">Key to test</param>
 /// <returns>True if the key is not null and contained inside the globale subspace</returns>
 public bool Contains(Slice key)
 {
     return(key.HasValue && m_globalSpace.Contains(key));
 }