Returns the value set in this context, or None, for each address in
        addresses.

        Args:
            addresses (list of str): The addresses to return values for, if set
                within this context.

        Returns:
            (list): bytes set at the address or None

def get_if_set(self, addresses):
        """Returns the value set in this context, or None, for each address in
        addresses.

        Args:
            addresses (list of str): The addresses to return values for, if set
                within this context.

        Returns:
            (list): bytes set at the address or None
        """

        with self._lock:
            results = []
            for add in addresses:
                results.append(self._get_if_set(add))
            return results