De-serializes the `Field` from the byte *buffer* starting at
        the begin of the *buffer* or with the given *index* by unpacking the
        bytes to the :attr:`value` of the `Field` in accordance with the
        decoding *byte order* for the de-serialization and the decoding
        :attr:`byte_order` of the `Field`.

        The specific decoding :attr:`byte_order` of the `Field` overrules the
        decoding *byte order* for the de-serialization.

        Returns the :class:`Index` of the *buffer* after the `Field`.

        Optional the de-serialization of the referenced :attr:`~Pointer.data`
        object of a :class:`Pointer` field can be enabled.

        :param bytes buffer: byte stream.
        :param Index index: current read :class:`Index` within the *buffer*.
        :keyword byte_order: decoding byte order for the de-serialization.
        :type byte_order: :class:`Byteorder`, :class:`str`
        :keyword bool nested: if ``True`` a :class:`Pointer` field de-serialize
            its referenced :attr:`~Pointer.data` object as well
            (chained method call).
            Each :class:`Pointer` field uses for the de-serialization of its
            referenced :attr:`~Pointer.data` object its own
            :attr:`~Pointer.bytestream`.

def deserialize(self, buffer=bytes(), index=Index(), **options):
        """ De-serializes the `Field` from the byte *buffer* starting at
        the begin of the *buffer* or with the given *index* by unpacking the
        bytes to the :attr:`value` of the `Field` in accordance with the
        decoding *byte order* for the de-serialization and the decoding
        :attr:`byte_order` of the `Field`.

        The specific decoding :attr:`byte_order` of the `Field` overrules the
        decoding *byte order* for the de-serialization.

        Returns the :class:`Index` of the *buffer* after the `Field`.

        Optional the de-serialization of the referenced :attr:`~Pointer.data`
        object of a :class:`Pointer` field can be enabled.

        :param bytes buffer: byte stream.
        :param Index index: current read :class:`Index` within the *buffer*.
        :keyword byte_order: decoding byte order for the de-serialization.
        :type byte_order: :class:`Byteorder`, :class:`str`
        :keyword bool nested: if ``True`` a :class:`Pointer` field de-serialize
            its referenced :attr:`~Pointer.data` object as well
            (chained method call).
            Each :class:`Pointer` field uses for the de-serialization of its
            referenced :attr:`~Pointer.data` object its own
            :attr:`~Pointer.bytestream`.
        """
        self.index = index
        self._value = self.unpack(buffer, index, **options)
        return self.index_field(index)