code: DBConn getDBConnection() {
          DBConn dbConn = null;
          synchronized (m_dbConns) {
              if (m_dbConns.size() > 0) {
                  dbConn = m_dbConns.poll();
              } else {
                  dbConn = createAndConnectConn(m_keyspace);
              }
          }
          return dbConn;
      }
docs: Get an available database connection from the pool, creating a new one if needed.