input: 
  def create_rectangle(length: float, width: float) -> 'Rectangle':
      """ Creates a Rectangle object with the given length and width.
      >>> create_rectangle(4.0, 5.0).area()
      20.0
      >>> create_rectangle(2.5, 6.0).area()
      15.0
      """
  
output:     class Rectangle:
          def __init__(self, length, width):
              self.length = length
              self.width = width
          
          def area(self):
              return self.length * self.width
      
      return Rectangle(length, width)