code: def area(self):
          
  
          self.normalize()
          area = 0.0
  
          for (order, cells) in self:
              area += (len(cells) * pi) / (3 * 4 ** order)
  
          return area
docs: The area enclosed by the MOC, in steradians.
  
          >>> m = MOC(0, (0, 1, 2))
          >>> round(m.area, 2)
          3.14