code: private void purgeAllConnections() {
          synchronized (m_dbConns) {
              Iterator<DBConn> iter = m_dbConns.iterator();
              while (iter.hasNext()) {
                  DBConn dbConn = iter.next();
                  dbConn.close();
                  iter.remove();
              }
          }
      }
docs: Close and delete all db connections, e.g., 'cause we're shutting down.