def METHOD_NAME(self, *documents: Union[List[Dict], List[List[Dict]]]) -> List[IndexAction]:
    """Add documents to upload to the Azure search index.
    An upload action is similar to an "upsert" where the document will be
    inserted if it is new and updated/replaced if it exists. All fields are
    replaced in the update case.
    :param documents: Documents to upload to an Azure search index. May be
     a single list of documents, or documents as individual parameters.
    :type documents: Dict or List[Dict]
    :return: the added actions
    :rtype: List[IndexAction]
    """
    return self._extend_batch(_flatten_args(documents), "upload")