def add_keyed(self, value, key, date=None, return_value=False):
        """Add keyed metrics data to collection.

        Args:
            value (str): The value of the metric.
            key (str): The key value for keyed metrics.
            date (str, optional): The optional date of the metric.
            return_value (bool, default:False): Tell the API to return the updates metric value.

        Return:
            dict: If return_value is True a dict with the current value for the time period
                is returned.
        """
        return self.add(value, date, return_value, key)
Add keyed metrics data to collection.

        Args:
            value (str): The value of the metric.
            key (str): The key value for keyed metrics.
            date (str, optional): The optional date of the metric.
            return_value (bool, default:False): Tell the API to return the updates metric value.

        Return:
            dict: If return_value is True a dict with the current value for the time period
                is returned.