Perform a resumable upload.

        Assumes ``chunk_size`` is not :data:`None` on the current blob.

        The content type of the upload will be determined in order
        of precedence:

        - The value passed in to this method (if not :data:`None`)
        - The value stored on the current blob
        - The default value ('application/octet-stream')

        :type client: :class:`~google.cloud.storage.client.Client`
        :param client: (Optional) The client to use.  If not passed, falls back
                       to the ``client`` stored on the blob's bucket.

        :type stream: IO[bytes]
        :param stream: A bytes IO object open for reading.

        :type content_type: str
        :param content_type: Type of content being uploaded (or :data:`None`).

        :type size: int
        :param size: The number of bytes to be uploaded (which will be read
                     from ``stream``). If not provided, the upload will be
                     concluded once ``stream`` is exhausted (or :data:`None`).

        :type num_retries: int
        :param num_retries: Number of upload retries. (Deprecated: This
                            argument will be removed in a future release.)

        :type predefined_acl: str
        :param predefined_acl: (Optional) predefined access control list

        :rtype: :class:`~requests.Response`
        :returns: The "200 OK" response object returned after the final chunk
                  is uploaded.

def _do_resumable_upload(
        self, client, stream, content_type, size, num_retries, predefined_acl
    ):
        """Perform a resumable upload.

        Assumes ``chunk_size`` is not :data:`None` on the current blob.

        The content type of the upload will be determined in order
        of precedence:

        - The value passed in to this method (if not :data:`None`)
        - The value stored on the current blob
        - The default value ('application/octet-stream')

        :type client: :class:`~google.cloud.storage.client.Client`
        :param client: (Optional) The client to use.  If not passed, falls back
                       to the ``client`` stored on the blob's bucket.

        :type stream: IO[bytes]
        :param stream: A bytes IO object open for reading.

        :type content_type: str
        :param content_type: Type of content being uploaded (or :data:`None`).

        :type size: int
        :param size: The number of bytes to be uploaded (which will be read
                     from ``stream``). If not provided, the upload will be
                     concluded once ``stream`` is exhausted (or :data:`None`).

        :type num_retries: int
        :param num_retries: Number of upload retries. (Deprecated: This
                            argument will be removed in a future release.)

        :type predefined_acl: str
        :param predefined_acl: (Optional) predefined access control list

        :rtype: :class:`~requests.Response`
        :returns: The "200 OK" response object returned after the final chunk
                  is uploaded.
        """
        upload, transport = self._initiate_resumable_upload(
            client,
            stream,
            content_type,
            size,
            num_retries,
            predefined_acl=predefined_acl,
        )

        while not upload.finished:
            response = upload.transmit_next_chunk(transport)

        return response