new_contents: from gypsy import increment
  
  def test_increment_basal_area_pl():
      args = []
      expected = None
      result = increment.increment_basal_area_pl(*args)
      assert result == expected
      # TODO: known value
      # TODO: 0 as an input
      # TODO: negative as an input
  
  
  def test_increment_basal_area_aw():
      args = []
      expected = None
      result = increment.increment_basal_area_aw(*args)
      assert result == expected
      # TODO: known value
      # TODO: 0 as an input
      # TODO: negative as an input
  
  
  def test_increment_basal_area_sb():
      args = []
      expected = None
      result = increment.increment_basal_area_sb(*args)
      assert result == expected
      # TODO: known value
      # TODO: 0 as an input
      # TODO: negative as an input
  
  
  def test_increment_basal_area_sw():
      args = []
      expected = None
      result = increment.increment_basal_area_sw(*args)
      assert result == expected
      # TODO: known value
      # TODO: 0 as an input
      # TODO: negative as an input
  
  
subject: Add boilerplate for increment tests