def htrc_get_titles(metadata, vol_id):
    """
    Gets titles of the volume given the metadata from a json file
    and volume id.
    """
    try:
        md = metadata[vol_id]
        return md[md.keys()[0]]['titles']

    except __HOLE__:
        print 'Volume ID not found:', vol_id
        raise
dataset/ETHPy150Open inpho/vsm/vsm/extensions/htrc.py/htrc_get_titles