How to use the desert.circle.from_json function in desert

pprint(s)
  pprint(stroke.from_json(s).json())
  pprint()

  c = circle(0.05, ((0.5, 0.4), (0.8, 0.4)), 1.0).json()
  pprint(c)
  pprint(circle.from_json(c).json())
  pprint()

  c = circle(0.05, ((0.5, 0.4), (0.8, 0.4)), 1.0)\
      .rgb([
          black(0.3),
          black(0.1)]).json()
  pprint(c)
  pprint(circle.from_json(c).json())
  pprint()

  r = rgb(0.1, 0.4, 0.3, 0.99).json()
  pprint(r)
  pprint(Rgba.from_json(r).json())
  pprint()

  b = bzspl([[(0.1, 0.2),
              (0.4, 0.25),
              (0.9, 0.15),
              (0.9, 0.3),
              (0.95, 0.45),
              (0.8, 0.9)]], 2, closed=True).json()

  pprint(b)
  pprint(bzspl.from_json(b).json())

s = stroke(((0.1, 0.1),
              (0.1, 0.1),
              (0.1, 0.9),
              (0.1, 0.1)),
             ((0.9, 0.9),
              (0.1, 0.9),
              (0.9, 0.9),
              (0.2, 0.15)), 2).rgb(black(0.4)).json()

  pprint(s)
  pprint(stroke.from_json(s).json())
  pprint()

  c = circle(0.05, ((0.5, 0.4), (0.8, 0.4)), 1.0).json()
  pprint(c)
  pprint(circle.from_json(c).json())
  pprint()

  c = circle(0.05, ((0.5, 0.4), (0.8, 0.4)), 1.0)\
      .rgb([
          black(0.3),
          black(0.1)]).json()
  pprint(c)
  pprint(circle.from_json(c).json())
  pprint()

  r = rgb(0.1, 0.4, 0.3, 0.99).json()
  pprint(r)
  pprint(Rgba.from_json(r).json())
  pprint()

  b = bzspl([[(0.1, 0.2),