docs: protected void closeConnectionSurrogate() throws Throwable {
  
          ConnectionPool connectionPool = this.connectionPool;
  
          if (connectionPool == null) {
  
              // CHECKME: policy?
              // pool has "disapeared" or was never provided (why?): should
              // "really" close the connection since it will no be reused.
              Connection connection = (Connection) this.delegate;
  
              try {
                  connection.close();
              } catch (SQLException ex) {}
          } else {
              Connection    connection    = (Connection) this.delegate;
              StatementPool statementPool = this.statementPool;
  
              connectionPool.checkIn(connection, statementPool);
          }
      }