def to_bytes(self, *, exclude=tuple()):
        """Serialize the pipe to a bytestring.

        exclude (Iterable[str]): String names of serialization fields to exclude.
        RETURNS (bytes): The serialized object.

        DOCS: https://spacy.io/api/entitylinker#to_bytes
        """
        self._validate_serialization_attrs()
        serialize = {}
        if hasattr(self, "cfg") and self.cfg is not None:
            serialize["cfg"] = lambda: srsly.json_dumps(self.cfg)
        serialize["vocab"] = lambda: self.vocab.to_bytes(exclude=exclude)
        serialize["kb"] = self.kb.to_bytes
        serialize["model"] = self.model.to_bytes
        return util.to_bytes(serialize, exclude)
Serialize the pipe to a bytestring.

        exclude (Iterable[str]): String names of serialization fields to exclude.
        RETURNS (bytes): The serialized object.

        DOCS: https://spacy.io/api/entitylinker#to_bytes
        
spacy/pipeline/entity_linker.py