code: def buffer(self, distance):
          
          distance = float(distance)
  
          buffered = Cylinder(
              height=self.primitive.height + distance * 2,
              radius=self.primitive.radius + distance,
              transform=self.primitive.transform.copy())
          return buffered
docs: Return a cylinder primitive which covers the source cylinder
          by distance: radius is inflated by distance, height by twice
          the distance.
  
          Parameters
          ------------
          distance : float
            Distance to inflate cylinder radius and height
  
          Returns
          -------------
          buffered : Cylinder
           Cylinder primitive inflated by distance