new_contents: 
  import pytest
  has_special_dependencies = False
  
  try:
      import netCDF4
      import xarray as xr
      has_special_dependencies = True
  
  except ImportError:
      pass
  
  
  @pytest.mark.skipif(
      not has_special_dependencies, 
      reason='No modules netCDF4, xarray')
  def test_xarray_upload(api1, auth1):
      # def test_xarray_upload(api1, local_auth):
  
      api1.attach_authority('auth', auth1)
      # api1.attach_authority('auth', local_auth)
      
      airtemps = xr.tutorial.load_dataset('air_temperature')
  
      archive = api1.create('big_archive')
  
      with archive.get_local_path() as f:
          airtemps.to_netcdf(f)
  
      for i in range(2):
  
          with archive.get_local_path() as f:
              with xr.open_dataset(f) as ds:
                  ds.load()
  
          assert (ds == airtemps*(2^i)).all()
  
          with archive.get_local_path() as f:
              (ds*2).to_netcdf(f)
  
          ds.close()
  
  
      airtemps.close()
subject: add big_dataset test