def get_version(gdbdr):
    """Get Reactome version."""
    version = None
    query = 'MATCH (v:DBInfo) RETURN v'
    with gdbdr.session() as session:
        for rec in session.run(query).records():
            dbinfo = rec['v']
            assert dbinfo.get('name') == 'reactome'
            version = dbinfo.get('version')
    assert version is not None
    return version
