def get_size(
            self,
            bucket: str,
            key: str
    ) -> int:
        """
        Retrieves the filesize
        :param bucket: the bucket the object resides in.
        :param key: the key of the object for which size is being retrieved.
        :return: integer equal to filesize in bytes
        """
        try:
            response = self.get_all_metadata(bucket, key)
            size = response['ContentLength']
            return size
        except botocore.exceptions.ClientError as ex:
            if str(ex.response['Error']['Code']) == str(requests.codes.not_found):
                raise BlobNotFoundError(f"Could not find s3://{bucket}/{key}") from ex
            raise BlobStoreUnknownError(ex)
Retrieves the filesize
        :param bucket: the bucket the object resides in.
        :param key: the key of the object for which size is being retrieved.
        :return: integer equal to filesize in bytes