    def build_shared_embeddings(
        dicts: Dict[str, Dictionary],
        langs: List[str],
        embed_dim: int,
        build_embedding: callable,
        pretrained_embed_path: Optional[str] = None,
    ):
        """
        Helper function to build shared embeddings for a set of languages after
        checking that all dicts corresponding to those languages are equivalent.

        Args:
            dicts: Dict of lang_id to its corresponding Dictionary
            langs: languages that we want to share embeddings for
            embed_dim: embedding dimension
            build_embedding: callable function to actually build the embedding
            pretrained_embed_path: Optional path to load pretrained embeddings
        """
        shared_dict = dicts[langs[0]]
        if any(dicts[lang] != shared_dict for lang in langs):
            raise ValueError(
                "--share-*-embeddings requires a joined dictionary: "
                "--share-encoder-embeddings requires a joined source "
                "dictionary, --share-decoder-embeddings requires a joined "
                "target dictionary, and --share-all-embeddings requires a "
                "joint source + target dictionary."
            )
        return build_embedding(shared_dict, embed_dim, pretrained_embed_path)
Helper function to build shared embeddings for a set of languages after
checking that all dicts corresponding to those languages are equivalent.

Args:
dicts: Dict of lang_id to its corresponding Dictionary
langs: languages that we want to share embeddings for
embed_dim: embedding dimension
build_embedding: callable function to actually build the embedding
pretrained_embed_path: Optional path to load pretrained embeddings
fairseq/models/fairseq_model.py