code: def _get_regions_element(
      self, selected: List[str]
  ) -> ConfigMultiElement:
      element = ConfigMultiElement(selected=selected)
      for r in REGIONS:
          element.values.append(ConfigElementValue(value=r, label=r))
      return element
  
imports: import json
  from typing import List
  from requests import HTTPError
  from dstack._internal.core.backends.base import Backend
  from dstack._internal.core.backends.lambdalabs import LambdaBackend, api_client
  from dstack._internal.core.backends.lambdalabs.config import LambdaConfig
  from dstack._internal.core.errors import BackendInvalidCredentialsError
  from dstack._internal.core.models.backends.base import BackendType, ConfigElementValue, ConfigMultiElement
  from dstack._internal.core.models.backends.lambdalabs import AnyLambdaConfigInfo, LambdaConfigInfo, LambdaConfigInfoWithCreds, LambdaConfigInfoWithCredsPartial, LambdaConfigValues, LambdaCreds, LambdaStoredConfig
  from dstack._internal.server.models import BackendModel, ProjectModel
  from dstack._internal.server.services.backends.configurators.base import Configurator, raise_invalid_credentials_error
label_desc: Use image node_id 8 for calling the LambdaConfigurator obj's underlying member method code with example usage: obj._get_regions_element(selected) and returns: element