code: def dask_chroms(data, samples):
      
      
      ## example concatenating with dask
      h5s = [os.path.join(data.dirs.across, s.name+".tmp.h5") for s in samples]
      handles = [h5py.File(i) for i in h5s]
      dsets = [i['/ichrom'] for i in handles]
      arrays = [da.from_array(dset, chunks=(10000, 3)) for dset in dsets]
      stack = da.stack(arrays, axis=2)
  
      ## max chrom (should we check for variable hits? if so, things can get wonk)
      maxchrom = da.max(stack, axis=2)[:, 0]
  
      ## max pos
      maxpos = da.max(stack, axis=2)[:, 2]
  
      ## min pos
      mask = stack == 0
      stack[mask] = 9223372036854775807  ## max int64 value
      minpos = da.min(stack, axis=2)[:, 1]
      final = da.stack([maxchrom, minpos, maxpos], axis=1)
      final.to_hdf5(data.clust_database, "/chroms")
  
      ## close the h5 handles
      _ = [i.close() for i in handles]
docs: A dask relay function to fill chroms for all samples