code: def deserialize(self, buffer=bytes(), index=Index(), **options):
          
          self.index = index
          self._value = self.unpack(buffer, index, **options)
          return self.index_field(index)
docs: 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`.