input: Write a function to create a Python class called Rectangle that represents a two-dimensional rectangle with a given length and width. The class should have a method named area that returns the area of the rectangle. Provide assertions to test the functionality of the class.
  
  class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width
  
  assert Rectangle(4, 5).area() == 20
  assert Rectangle(7, 3).area() == 21
  assert Rectangle(2, 2).area() == 4
  assert Rectangle(10, 1).area() == 10
  assert Rectangle(0, 1).area() == 0
output: class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width