def _check_and_update_params(self, required, params):
        """
        Ensure all required parameters were passed to the API call and format
        them correctly.
        """
        for r in required:
            if params not in r:
                raise PayPalError("Missing required param: %s" % r)

        # Upper case all the parameters for PayPal.
        return (dict((k.upper(), v) for k, v in params.items()))
dataset/ETHPy150Open spookylukey/django-paypal/paypal/pro/helpers.py/PayPalWPP._check_and_update_params/swapped operands of `not in`