new_contents: from itertools import zip_longest as zlong
  import pytest
  import f90nml
  import pandas
  import stagpy.stagyydata
  
  def test_sdat_path(example_dir, sdat):
      assert sdat.path == example_dir
  
  def test_sdat_par(sdat):
      assert isinstance(sdat.par, f90nml.namelist.Namelist)
  
  def test_sdat_tseries(sdat):
      assert isinstance(sdat.tseries, pandas.DataFrame)
  
  def test_sdat_rprof(sdat):
      assert isinstance(sdat.rprof, pandas.DataFrame)
  
  def test_sdat_walk_dflt(sdat):
      wlk = iter(sdat.walk)
      assert next(wlk) is sdat.snaps[-1]
      with pytest.raises(StopIteration):
          next(wlk)
  
  def test_steps_iter(sdat):
      assert all(a is b for a, b in zlong(sdat.steps, sdat.steps[:]))
  
  def test_snaps_iter(sdat):
      assert all(a is b for a, b in zlong(sdat.snaps, sdat.snaps[:]))
  
  def test_filter_snap(sdat):
      snaps = (s for s in sdat.snaps if s.istep is not None)
      assert all(
          a is b for a, b in zlong(snaps, sdat.steps.filter(snap=True)))
  
  def test_filter_even_steps(sdat):
      even = lambda step: step.istep % 2 == 0
      assert all(
          a is b for a,b in zlong(sdat.steps[::2], sdat.steps.filter(func=even)))
  
  def test_snaps_last(sdat):
      assert sdat.snaps.last is sdat.snaps[-1]
  
  def test_snaps_empty(sdat):
      empty = sdat.snaps[len(sdat.snaps)]
      assert isinstance(empty, stagpy.stagyydata._EmptyStep)
  
  def test_step_is_snap(sdat):
      istep = sdat.snaps.last.istep
      assert sdat.steps[istep] is sdat.snaps.last
  
  def test_step_sdat(sdat):
      assert all(s.sdat is sdat for s in sdat.steps)
  
  def test_step_istep(sdat):
      assert all(s is sdat.steps[s.istep] for s in sdat.steps)
  
  def test_geom_refs(step):
      assert step.geom is step.fields.geom
  
  def test_geom_twod(step):
      assert step.geom.twod
  
subject: Add tests of stagpy.stagyydata