text: from nanopores.tools.box import Box
  
  square = Box((0, 0), (4, 4))
  lshape = Box((1, 1), (3, 3)) - Box((2, 2), (3, 3))
  
  square.addsubdomain(lshape, "lshape")
  square.addboundaries(   
      allb = (square - lshape).boundary(),
  )
  geo = square.create_geometry(lc=.2)
  
  square2 = square.copy()
  geo = square2.create_geometry(lc=.2, merge=False)
  
  square.plot()
  square2.plot()