text: from sfsimodels.models import loads
  
  
  def test_loads_add_and_remove():
      load = loads.Load(p_x=10)
      assert load.p_x == 10
      assert load.p_y is None
      load.p_x = 15
      load.p_y = 9
      assert load.p_x == 15
      assert load.p_y == 9
      load.p_z = 3
      load.t_xx = 4
      load.t_yy = 5
      load.t_zz = 6
      assert load.p_z == 3
      assert load.t_xx == 4
      assert load.t_yy == 5
      assert load.t_zz == 6
  
  
  def test_load_at_coords_add_and_remove():
      load = loads.LoadAtCoords(p_x=10, x=3)
      assert load.p_x == 10
      assert load.p_y is None
      load.p_x = 15
      load.p_y = 9
      assert load.p_x == 15
      assert load.p_y == 9
      load.p_z = 3
      load.t_xx = 4
      load.t_yy = 5
      load.t_zz = 6
      assert load.p_z == 3
      assert load.t_xx == 4
      assert load.t_yy == 5
      assert load.t_zz == 6
      assert load.x == 3
  