code: def _open(self, db, writeAccess=False):
          
          if not pymysql:
              raise orb.errors.BackendNotFound('psycopg2 is not installed.')
  
          # create the python connection
          try:
              return pymysql.connect(db=db.name(),
                                     user=db.username(),
                                     passwd=db.password(),
                                     host=(db.writeHost() if writeAccess else db.host()) or 'localhost',
                                     port=db.port() or 3306,
                                     cursorclass=pymysql.cursors.DictCursor)
          except pymysql.OperationalError as err:
              log.exception('Failed to connect to postgres')
              raise orb.errors.ConnectionFailed()
docs: Handles simple, SQL specific connection creation.  This will not
          have to manage thread information as it is already managed within
          the main open method for the SQLBase class.
  
          :param      db | <orb.Database>
  
          :return     <variant> | backend specific database connection