code: def cognito_idp_user_pool_arn(self, lookup, default=None):
      
      client = EFAwsResolver.__CLIENTS["cognito-idp"]
      user_pool_id = self.cognito_idp_user_pool_id(lookup, default)
      if user_pool_id == default:
        return default
  
      response = client.describe_user_pool(UserPoolId=user_pool_id)
  
      if not response.has_key("UserPool"):
        return default
  
      return response["UserPool"]["Arn"]
docs: Args:
          lookup: Cognito User Pool name, proto0-cms-user-pool
          default: the optional value to return if lookup failed; returns None if not set
  
      Returns:
          the User Pool ARN corresponding to the given lookup, else default/None