code: def create_backend(
      self, project: ProjectModel, config: GCPConfigInfoWithCreds
  ) -> BackendModel:
      if config.regions is None:
          config.regions = DEFAULT_REGIONS
      credentials, _ = auth.authenticate(creds=config.creds)
      service_account_email = getattr(
          credentials, "service_account_email", None
      )
      if service_account_email is None:
          service_account_email = self._get_or_create_service_account(
              credentials=credentials,
              project_id=config.project_id,
              name=gcp_utils.get_service_account_name(project.name),
          )
          self._grant_roles_to_service_account(
              credentials=credentials,
              project_id=config.project_id,
              service_account_email=service_account_email,
          )
      return BackendModel(
          project_id=project.id,
          type=self.TYPE.value,
          config=GCPStoredConfig(
              **GCPConfigInfo.parse_obj(config).dict(),
              service_account_email=service_account_email,
          ).json(),
          auth=GCPCreds.parse_obj(config.creds).json(),
      )
  
imports: import json
  from typing import Dict, List
  import googleapiclient.discovery
  import googleapiclient.errors
  from google.auth.credentials import Credentials
  from dstack._internal.core.backends.gcp import GCPBackend, auth
  from dstack._internal.core.backends.gcp import utils
  from dstack._internal.core.backends.gcp.config import GCPConfig
  from dstack._internal.core.errors import BackendAuthError, ServerClientError
  from dstack._internal.core.models.backends.base import BackendType, ConfigElement, ConfigElementValue, ConfigMultiElement
  from dstack._internal.core.models.backends.gcp import AnyGCPConfigInfo, GCPConfigInfo, GCPConfigInfoWithCreds, GCPConfigInfoWithCredsPartial, GCPConfigValues, GCPCreds, GCPDefaultCreds, GCPServiceAccountCreds, GCPStoredConfig
  from dstack._internal.server import settings
  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 3 for calling the GCPConfigurator obj's underlying member method code with example usage: obj.create_backend(project, config) and returns: BackendModel