add additional filename parameter
add additional filename parameter

clarkfitzg/dask,mrocklin/dask,jakirkham/dask,ContinuumIO/dask,ssanderson/dask,clarkfitzg/dask,gameduell/dask,jcrist/dask,pombredanne/dask,vikhyat/dask,dask/dask,mraspaud/dask,blaze/dask,dask/dask,PhE/dask,ssanderson/dask,chrisbarber/dask,blaze/dask,ContinuumIO/dask,mraspaud/dask,jakirkham/dask,jcrist/dask,mrocklin/dask,cowlicks/dask,vikhyat/dask,PhE/dask,mikegraham/dask,pombredanne/dask,cpcloud/dask