input: Write a function to draw a fish using the turtle module.
  assert isinstance(draw_fish(), type(None))
output: def draw_fish():
      import turtle
  
      screen = turtle.Screen()
      screen.setup(800, 600)
      screen.title("Fish Drawing")
  
      fish = turtle.Turtle()
      fish.speed(2)
  
      # Draw fish body
      fish.penup()
      fish.goto(-100, 0)
      fish.pendown()
      fish.begin_fill()
      fish.color("orange")
      fish.circle(100, 180)  # upper semicircle
      fish.right(90)
      fish.forward(200)
      fish.right(90)
      fish.circle(100, 180)  # lower semicircle
      fish.right(90)
      fish.forward(200)
      fish.end_fill()
  
      # Draw fish tail
      fish.penup()
      fish.goto(-100, 0)
      fish.pendown()
      fish.begin_fill()
      fish.color("red")
      fish.left(135)
      fish.forward(100)
      fish.right(90)
      fish.forward(100)
      fish.right(135)
      fish.forward(140)
      fish.end_fill()
  
      # Draw fish eye
      fish.penup()
      fish.goto(50, 50)
      fish.pendown()
      fish.begin_fill()
      fish.color("white")
      fish.circle(10)
      fish.end_fill()
  
      # Draw fish pupil
      fish.penup()
      fish.goto(55, 55)
      fish.pendown()
      fish.begin_fill()
      fish.color("black")
      fish.circle(5)
      fish.end_fill()
  
      fish.hideturtle()
      screen.mainloop()