new_contents: import numpy as np
  import pytest
  from sklearn.utils.testing import (
      assert_array_equal
  )
  from scipy import sparse
  
  from anndata.tests.helpers import (
      gen_adata,
      subset_func,
      asarray
  )
  
  @pytest.fixture(
      params=[np.array, sparse.csr_matrix, sparse.csc_matrix],
      ids=["np_array", "scipy_csr", "scipy_csc"]
  )
  def matrix_type(request):
      return request.param
  
  # TODO: Test values of .uns
  def test_inplace_subset_var(matrix_type, subset_func):
      orig = gen_adata((30, 30), X_type=matrix_type)
      subset_idx = subset_func(orig.var_names)
  
      modified = orig.copy()
      from_view = orig[:, subset_idx].copy()
      modified._inplace_subset_var(subset_idx)
  
      assert_array_equal(asarray(from_view.X), asarray(modified.X))
      assert_array_equal(from_view.obs, modified.obs)
      assert_array_equal(from_view.var, modified.var)
      for k in from_view.obsm:
          assert_array_equal(asarray(from_view.obsm[k]), asarray(modified.obsm[k]))
          assert_array_equal(asarray(orig.obsm[k]), asarray(modified.obsm[k]))
      for k in from_view.varm:
          assert_array_equal(asarray(from_view.varm[k]), asarray(modified.varm[k]))
      for k in from_view.layers:
          assert_array_equal(asarray(from_view.layers[k]), asarray(modified.layers[k]))
  
  def test_inplace_subset_obs(matrix_type, subset_func):
      orig = gen_adata((30, 30), X_type=matrix_type)
      subset_idx = subset_func(orig.obs_names)
  
      modified = orig.copy()
      from_view = orig[subset_idx, :].copy()
      modified._inplace_subset_obs(subset_idx)
  
      assert_array_equal(asarray(from_view.X), asarray(modified.X))
      assert_array_equal(from_view.obs, modified.obs)
      assert_array_equal(from_view.var, modified.var)
      for k in from_view.obsm:
          assert_array_equal(asarray(from_view.obsm[k]), asarray(modified.obsm[k]))
      for k in from_view.varm:
          assert_array_equal(asarray(from_view.varm[k]), asarray(modified.varm[k]))
          assert_array_equal(asarray(orig.varm[k]), asarray(modified.varm[k]))
      for k in from_view.layers:
          assert_array_equal(asarray(from_view.layers[k]), asarray(modified.layers[k]))
  
subject: Add tests for inplace subset