old_contents: import pandas as pd
  import pytest
  
  from vivarium.framework.population import PopulationView, PopulationManager, PopulationError
  
  
  class DummyPopulationManager:
      def __init__(self):
          self.population = pd.DataFrame({'age': [0, 10, 20, 30, 40, 50, 60, 70], 'sex': ['Male', 'Female']*4})
  
  
  def test_create_PopulationView_with_all_columns():
      manager = DummyPopulationManager()
      view = PopulationView(manager)
      assert set(view.columns) == {'age', 'sex'}
  
  
  # test dependencies
  def test_circular_initializers():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ['init_1_column'], ['init_2_column'])
      manager.register_simulant_initializer(lambda: "initializer 2",
                                            ['init_2_column'], ['init_1_column'])
      with pytest.raises(PopulationError, match="Check for cyclic dependencies"):
          manager._order_initializers()
  
  
  def test_missing_initializer():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ["result_column"], ["input_column"])
      with pytest.raises(PopulationError, match="Check for missing dependencies"):
          manager._order_initializers()
  
  
  def test_conflicting_initializers():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ['dummy_column'], [])
      manager.register_simulant_initializer(lambda: "initializer 2",
                                            ['dummy_column'], [])
      with pytest.raises(PopulationError, match="Multiple components are attempting "
                                                "to initialize the same columns"):
          manager._order_initializers()
new_contents: import pandas as pd
  import pytest
  
  from vivarium.framework.population import PopulationView, PopulationManager, PopulationError
  
  
  class DummyPopulationManager:
      def __init__(self):
          self.population = pd.DataFrame({'age': [0, 10, 20, 30, 40, 50, 60, 70], 'sex': ['Male', 'Female']*4})
  
  
  def test_create_PopulationView_with_all_columns():
      manager = DummyPopulationManager()
      view = PopulationView(manager)
      assert set(view.columns) == {'age', 'sex'}
  
  
  def test_circular_initializers():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ['init_1_column'], ['init_2_column'])
      manager.register_simulant_initializer(lambda: "initializer 2",
                                            ['init_2_column'], ['init_1_column'])
      with pytest.raises(PopulationError, match="Check for cyclic dependencies"):
          manager._order_initializers()
  
  
  def test_missing_initializer():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ["result_column"], ["input_column"])
      with pytest.raises(PopulationError, match="Check for missing dependencies"):
          manager._order_initializers()
  
  
  def test_conflicting_initializers():
      manager = PopulationManager()
      manager.register_simulant_initializer(lambda: "initializer 1",
                                            ['result_column'], [])
      manager.register_simulant_initializer(lambda: "initializer 2",
                                            ['result_column'], [])
      with pytest.raises(PopulationError, match="Multiple components are attempting "
                                                "to initialize the same columns"):
          manager._order_initializers()
subject: remove comment, standardize column name