code: def _initialize(self, nebula_dict):
      self.enabled = get_scalar_param(
          nebula_dict, NEBULA_ENABLED, NEBULA_ENABLED_DEFAULT
      )
  
      self.load_path = get_scalar_param(
          nebula_dict, NEBULA_LOAD_PATH, NEBULA_LOAD_PATH_DEFAULT
      )
  
      self.enable_nebula_load = get_scalar_param(
          nebula_dict,
          NEBULA_ENABLE_NEBULA_LOAD,
          NEBULA_ENABLE_NEBULA_LOAD_DEFAULT,
      )
  
      self.persistent_storage_path = get_scalar_param(
          nebula_dict,
          NEBULA_PERSISTENT_STORAGE_PATH,
          NEBULA_PERSISTENT_STORAGE_PATH_DEFAULT,
      )
  
      self.persistent_time_interval = get_scalar_param(
          nebula_dict,
          NEBULA_PERSISTENT_TIME_INTERVAL,
          NEBULA_PERSISTENT_TIME_INTERVAL_DEFAULT,
      )
  
      self.num_of_version_in_retention = get_scalar_param(
          nebula_dict,
          NEBULA_NUM_OF_VERSION_IN_RETENTION,
          NEBULA_NUM_OF_VERSION_IN_RETENTION_DEFAULT,
      )
  
imports: from deepspeed.runtime.config_utils import get_scalar_param, DeepSpeedConfigObject
  from deepspeed.nebula.constants import *
label_desc: Use image node_id 2 for calling the DeepSpeedNebulaConfig obj's underlying member method code with example usage: obj._initialize(nebula_dict) without return types