input: Write a python function to create a simple spiderweb using the turtle module.
  assert isinstance(create_spiderweb(), type(None))
output: def create_spiderweb():
      import turtle
      import math
  
      def draw_circle(radius):
          turtle.penup()
          turtle.goto(0, -radius)
          turtle.pendown()
          turtle.circle(radius)
          turtle.penup()
          turtle.goto(0, 0)
          turtle.pendown()
  
      def draw_radial_line(angle, length):
          turtle.penup()
          turtle.goto(0, 0)
          turtle.setheading(angle)
          turtle.pendown()
          turtle.forward(length)
          turtle.penup()
          turtle.goto(0, 0)
          turtle.pendown()
  
      turtle.speed(0)
      turtle.hideturtle()
  
      number_of_circles = 5
      radius_step = 20
  
      for i in range(1, number_of_circles + 1):
          draw_circle(radius_step * i)
  
      number_of_radial_lines = 12
      angle_step = 360 / number_of_radial_lines
  
      for i in range(number_of_radial_lines):
          draw_radial_line(angle_step * i, radius_step * number_of_circles)
  
      turtle.done()