old_contents: """Builtin Datasets.
  """
  
  from scanpy.api import read
  import numpy as np
  
  
  def dentategyrus():
      """Dentate Gyrus dataset from Hochgerner et al. (2018).
      Dentate gyrus is part of the hippocampus involved in learning, episodic memory formation and spatial coding.
      It is measured using 10X Genomics Chromium and described in Hochgerner et al. (2018).
      The data consists of 25,919 genes across 3,396 cells and provides several interesting characteristics.
      """
      filename = 'data/DentateGyrus/10X43_1.loom'
      url = 'http://pklab.med.harvard.edu/velocyto/DG1/10X43_1.loom'
      adata = read(filename, backup_url=url, cleanup=True, sparse=True, cache=True)
      return adata
  
  
  def toy_data(n_obs):
      """Random samples from Dentate Gyrus.
      """
      adata = dentategyrus()
      indices = np.random.choice(adata.n_obs, n_obs)
      adata = adata[indices]
      adata.obs_names = range(adata.n_obs)
      return adata
  
new_contents: """Builtin Datasets.
  """
  
  from scanpy.api import read
  import numpy as np
  
  
  def dentategyrus():
      """Dentate Gyrus dataset from Hochgerner et al. (2018).
      Dentate gyrus is part of the hippocampus involved in learning, episodic memory formation and spatial coding.
      It is measured using 10X Genomics Chromium and described in Hochgerner et al. (2018).
      The data consists of 25,919 genes across 3,396 cells and provides several interesting characteristics.
      """
      filename = 'data/DentateGyrus/10X43_1.loom'
      url = 'http://pklab.med.harvard.edu/velocyto/DG1/10X43_1.loom'
      adata = read(filename, backup_url=url, cleanup=True, sparse=True, cache=True)
      return adata
  
  
  def toy_data(n_obs):
      """Random samples from Dentate Gyrus.
      """
      adata = dentategyrus()
      indices = np.random.choice(adata.n_obs, n_obs)
      adata = adata[indices]
      adata.obs_names = np.array(range(adata.n_obs), dtype='str')
      return adata
  
subject: fix obs_names for toy data