add optional model_revision to SentenceTransformer

sentence_transformers/SentenceTransformer.py

@@ -39,12 +39,14 @@ class SentenceTransformer(nn.Sequential):
     :param device: Device (like 'cuda' / 'cpu') that should be used for computation. If None, checks if a GPU can be used.
     :param cache_folder: Path to store models. Can be also set by SENTENCE_TRANSFORMERS_HOME enviroment variable.
     :param use_auth_token: HuggingFace authentication token to download private models.
+    :param model_revision: The specific model version to use. It can be a branch name, a tag name, or a commit id, for a stored model on huggingface.co.
     """
     def __init__(self, model_name_or_path: Optional[str] = None,
                  modules: Optional[Iterable[nn.Module]] = None,
                  device: Optional[str] = None,
                  cache_folder: Optional[str] = None,
-                 use_auth_token: Union[bool, str, None] = None
+                 use_auth_token: Union[bool, str, None] = None,
+                 model_revision: Optional[str] = None
                  ):
         self._model_card_vars = {}
         self._model_card_text = None
@@ -89,7 +91,8 @@ def __init__(self, model_name_or_path: Optional[str] = None,
                                         library_name='sentence-transformers',
                                         library_version=__version__,
                                         ignore_files=['flax_model.msgpack', 'rust_model.ot', 'tf_model.h5'],
-                                        use_auth_token=use_auth_token)
+                                        use_auth_token=use_auth_token,
+                                        revision=model_revision)
 
             if os.path.exists(os.path.join(model_path, 'modules.json')):    #Load as SentenceTransformer model
                 modules = self._load_sbert_model(model_path)