def METHOD_NAME(file: File, offset=0):
    file_with_offset = OffsetFile(file, offset)
    # First find the end of the last entry in the file
    last_offset = _get_end_of_last_tar_entry(file_with_offset)
    if last_offset == -1:
        return -1
    # Then find where the final zero blocks end
    return offset + _find_end_of_padding(file_with_offset, find_from=last_offset)