code: final void activate() throws SQLException {
        for(ConnectionPoolConnection conn : connections) {
           conn.forceRealClose();
           conn.realOpen();
           conn.logicalClose(true); //Tests the connection
        }
  
        if(closeQueue != null) {
           closeQueue.clear();
        }
  
        availableQueue.clear();
        reopenExecutor.getQueue().clear();
  
        List<ConnectionPoolConnection> connections = Lists.newArrayListWithCapacity(this.connections.length);
        for(ConnectionPoolConnection connection : this.connections) {
           connections.add(connection);
           connection.state.set(ConnectionPoolConnection.STATE_AVAILABLE);
        }
  
        isActive = true;
        stats.activate();
        availableQueue.addAll(connections);
     }
docs: Activates the segment by opening and testing all connections.
  @throws SQLException if connections could not be created.