code: public void removeDescriptor(Object validKey)
      {
          PBKey pbKey;
          if (validKey instanceof PBKey)
          {
              pbKey = (PBKey) validKey;
          }
          else if (validKey instanceof JdbcConnectionDescriptor)
          {
              pbKey = ((JdbcConnectionDescriptor) validKey).getPBKey();
          }
          else
          {
              throw new MetadataException("Could not remove descriptor, given object was no vaild key: " +
                      validKey);
          }
          Object removed = null;
          synchronized (jcdMap)
          {
              removed = jcdMap.remove(pbKey);
              jcdAliasToPBKeyMap.remove(pbKey.getAlias());
          }
          log.info("Remove descriptor: " + removed);
      }
docs: Remove a descriptor.
  @param validKey  This could be the {@link JdbcConnectionDescriptor}
  itself, or the associated {@link JdbcConnectionDescriptor#getPBKey PBKey}.