def __init__(self, database_factory=None, alphabet=None):
     self._default_db = DatabaseBuilder.get_default_db_instance() if database_factory is None else database_factory
     self.alphabet = "wWBLCMPZbH2GFszTogYu93JNDfIlVmneRx6tkAvKU51r8XOidpchEjQqS7a40y" if alphabet is None else alphabet
 def __init__(self):
     # DatabaseBuilder.run_mode = 'test'
     self._default_db = DatabaseBuilder.get_default_db_instance()