new_contents: """Test the output module."""
  
  frc_out = outputs.frc_eia923_df(pudl_engine)
  gens_out = outputs.gens_eia860_df(pudl_engine)
  gf_out = outputs.gf_eia923_df(pudl_engine)
  pu_eia = outputs.plants_utils_eia_df(pudl_engine)
  pu_ferc = outputs.plants_utils_ferc_df(pudl_engine)
  steam_out = outputs.plants_steam_ferc1_df(pudl_engine)
  fuel_out = outputs.fuel_ferc1_df(pudl_engine)
  
subject: Add skeletal output test cases.