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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def factory(cls, note, fn=None):
 """Register a function as a provider. Function (name support is optional):
: from jeni import Injector as BaseInjector from jeni import Provider class Injector(BaseInjector):
 pass @Injector.factory('echo') def echo(name=None):
 return name Registration can be a decorator or a direct method call:: Injector.factory('echo', echo) """

        def decorator(f):
            provider = cls.factory_provider.bind(f)
            cls.register(note, provider)
            return f

        if fn is not None:
            decorator(fn)
        else:
            return decorator