code: public static synchronized void registerDriver(java.sql.Driver driver)
          throws SQLException {
  
          /* Register the driver if it has not already been added to our list */
          if(driver != null) {
              registeredDrivers.addIfAbsent(new DriverInfo(driver));
          } else {
              // This is for compatibility with the original DriverManager
              throw new NullPointerException();
          }
  
          println("registerDriver: " + driver);
  
      }
docs: Registers the given driver with the <code>DriverManager</code>.
  A newly-loaded driver class should call
  the method <code>registerDriver</code> to make itself
  known to the <code>DriverManager</code>.
  
  @param driver the new JDBC Driver that is to be registered with the
  <code>DriverManager</code>
  @exception SQLException if a database access error occurs