input: Write a python function to create a Building object based on the given size and check the number of rooms.
  assert create_building("small").rooms == 2
  assert create_building("medium").rooms == 3
  assert create_building("large").rooms == 4
output: def create_building(size):
      class Building:
          def __init__(self, rooms):
              self.rooms = rooms
  
      if size == "small":
          return Building(2)
      elif size == "medium":
          return Building(3)
      elif size == "large":
          return Building(4)