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 include an initializer to set the length and width and a method to calculate the area of the rectangle.
  
  class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width
  
  assert Rectangle(5, 10).area() == 50
  assert Rectangle(3, 4).area() == 12
  assert Rectangle(0, 0).area() == 0
  assert Rectangle(7, 2).area() == 14
output: class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width