Load a chunk from file using Bounds info.
    Pass 'slow=True' for an alternative loading method based on line numbers.

def load_chunk(filename, bounds, encoding='utf8', slow=False):
    """
    Load a chunk from file using Bounds info.
    Pass 'slow=True' for an alternative loading method based on line numbers.
    """
    if slow:
        return _load_chunk_slow(filename, bounds, encoding)

    with open(filename, 'rb') as f:
        f.seek(bounds.byte_start)
        size = bounds.byte_end - bounds.byte_start
        return f.read(size).decode(encoding)