Python classes are defined as in the following example:

class Book(object):
    pass

Here the class is empty, without fields or methods, because the pass statement in Python does nothing; it just acts as a placeholder for possible future code.

Objects of a particular class are constructed by calling the constructor, which has the same name as the class and is invoked without any new keyword:

book = Book()

Define an empty class named Library and construct a Library object so that the actual outputs match the expected outputs.