properly handle fully consumed iterator
properly handle fully consumed iterator

dask/distributed,mrocklin/distributed,mrocklin/distributed,dask/distributed,broxtronix/distributed,amosonn/distributed,amosonn/distributed,broxtronix/distributed,amosonn/distributed,broxtronix/distributed,blaze/distributed,dask/distributed,dask/distributed,blaze/distributed,mrocklin/distributed