def METHOD_NAME(self, customer_id, params=None):
    if params is None:
        params = {}
    Resource.verify_keys(params, Customer.update_signature())
    self.__check_for_deprecated_attributes(params)
    response = self.config.http().put(self.config.base_merchant_path() + "/customers/" + customer_id, {"customer": params})
    if "customer" in response:
        return SuccessfulResult({"customer": Customer(self.gateway, response["customer"])})
    elif "api_error_response" in response:
        return ErrorResult(self.gateway, response["api_error_response"])