input: Write a function to create a Python class called Rectangle that represents a two-dimensional rectangle with a length and width. The class should have an initializer to set the length and width, and a method called area that returns the area of the rectangle. If the rectangle has a length of 5 and a width of 3, the area should return 15. If the rectangle has a length of 7 and a width of 4, the area should return 28. If either the length or the width is zero, the area should return 0.
  
  class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width
  
  assert Rectangle(5, 3).area() == 15
  assert Rectangle(7, 4).area() == 28
  assert Rectangle(0, 3).area() == 0
  assert Rectangle(5, 0).area() == 0
output: class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width