code: def get_catalog_options(self):
          
          # TODO: We will remove the discovery service catalog implementation
          # once we have fully migrated customer's to EnterpriseCustomerCatalogs.
          # For now, this code will prevent an admin from creating a new
          # EnterpriseCustomer with a discovery service catalog. They will have to first
          # save the EnterpriseCustomer admin form and then edit the EnterpriseCustomer
          # to add a discovery service catalog.
          if hasattr(self.instance, 'site'):
              catalog_api = CourseCatalogApiClient(self.user, self.instance.site)
          else:
              catalog_api = CourseCatalogApiClient(self.user)
          catalogs = catalog_api.get_all_catalogs()
          # order catalogs by name.
          catalogs = sorted(catalogs, key=lambda catalog: catalog.get('name', '').lower())
  
          return BLANK_CHOICE_DASH + [
              (catalog['id'], catalog['name'],)
              for catalog in catalogs
          ]
docs: Retrieve a list of catalog ID and name pairs.
  
          Once retrieved, these name pairs can be used directly as a value
          for the `choices` argument to a ChoiceField.