input: Write a python function to return a list of book titles from a given list of book dictionaries.
  assert get_book_titles([{'title': 'Book 1', 'author': 'John Doe', 'publisher': 'ABC Publisher'}, {'title': 'Book 2', 'author': 'Jane Doe', 'publisher': 'XYZ Publisher'}]) == ['Book 1', 'Book 2']
  assert get_book_titles([{'title': 'Python 101', 'author': 'Guido van Rossum', 'publisher': 'O'Reilly'}, {'title': 'Flask for Beginners', 'author': 'Armin Ronacher', 'publisher': 'Packt'}]) == ['Python 101', 'Flask for Beginners']
  assert get_book_titles([{'title': 'The Catcher in the Rye', 'author': 'J.D. Salinger', 'publisher': 'Little, Brown and Company'}]) == ['The Catcher in the Rye']
output: def get_book_titles(books):
      return [book['title'] for book in books]