/// <summary>
 ///     Access UID dictionary instance as array. DICOM
 ///     UIDs are used for indexing.
 /// </summary>
 public UidDictionaryEntry this[Uid index]
 {
     get
     {
         if (index != null)
         {
             return((UidDictionaryEntry)hashTable[index.ToString()]);
         }
         else
         {
             throw new DicomException("index is null.",
                                      "UidDictionary[index]");
         }
     }
 }
 /// <summary>
 ///     Determines whether a DICOM UID already is in use within a UID
 ///     dictionary instance.
 /// </summary>
 public bool Contains(Uid uid)
 {
     return(hashTable.Contains(uid.ToString()));
 }