input: Write a function to create a Python class called Rectangle that represents a two-dimensional rectangle with a length and width. Include 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(1, 1).area()==1
  assert Rectangle(7, 2).area()==14
  assert Rectangle(2, 2).area()==4
output: class Rectangle:
      def __init__(self, length, width):
          self.length = length
          self.width = width
  
      def area(self):
          return self.length * self.width