Returns the accumulated bit size of all fields in the `Sequence` as
        a tuple in the form of ``(number of bytes, remaining number of bits)``.

def container_size(self):
        """ Returns the accumulated bit size of all fields in the `Sequence` as
        a tuple in the form of ``(number of bytes, remaining number of bits)``.
        """
        length = 0
        for name, item in enumerate(self):
            # Container
            if is_container(item):
                byte_length, bit_length = item.container_size()
                length += bit_length + byte_length * 8
            # Field
            elif is_field(item):
                length += item.bit_size
            else:
                raise MemberTypeError(self, item, name)
        return divmod(length, 8)