input: Write a python function to create a Book object and print its details.
  assert create_and_print_book("1984", "George Orwell", "Secker & Warburg", 1949) == "Title: 1984\nAuthor: George Orwell\nPublisher: Secker & Warburg\nYear: 1949\n"
  assert create_and_print_book("To Kill a Mockingbird", "Harper Lee", "J.B. Lippincott & Co.", 1960) == "Title: To Kill a Mockingbird\nAuthor: Harper Lee\nPublisher: J.B. Lippincott & Co.\nYear: 1960\n"
  assert create_and_print_book("The Great Gatsby", "F. Scott Fitzgerald", "Charles Scribner's Sons", 1925) == "Title: The Great Gatsby\nAuthor: F. Scott Fitzgerald\nPublisher: Charles Scribner's Sons\nYear: 1925\n"
output: def create_and_print_book(title, author, publisher, year):
      class Book:
          def __init__(self, title, author, publisher, year):
              self.title = title
              self.author = author
              self.publisher = publisher
              self.year = year
  
          def __str__(self):
              return f"Title: {self.title}\nAuthor: {self.author}\nPublisher: {self.publisher}\nYear: {self.year}\n"
  
      book = Book(title, author, publisher, year)
      return str(book)