def chunk_iterator( gffs ):
    for gff in gffs:
        yield [gff,]
Removes any empty metadata values older than the timestamp using the
dataset/ETHPy150Open CGATOxford/cgat/obsolete/GFF.py/chunk_iterator--crossover with--dataset/ETHPy150Open openstack/swift/swift/common/db.py/DatabaseBroker._reclaim