def get_size(self, value=None):
        """Return the size in bytes.

        Args:
            value (bytes): In structs, the user can assign other value instead
                of this class' instance. Here, in such cases, ``self`` is a
                class attribute of the struct.

        Returns:
            int: The address size in bytes.

        """
        if value is None:
            value = self._value

        if hasattr(value, 'get_size'):
            return value.get_size()

        return len(self.pack(value))
Return the size in bytes.

        Args:
            value (bytes): In structs, the user can assign other value instead
                of this class' instance. Here, in such cases, ``self`` is a
                class attribute of the struct.

        Returns:
            int: The address size in bytes.