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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 require_initialized(exception):
 """ Decorator for API methods that should only be called after TradingAlgorithm.initialize. `exception` will be raised if the method is called before initialize has completed. Examples -------- @require_initialized(SomeException("Don't do that!")) def method(self):
 # Do stuff that should only be allowed after initialize. """

    def decorator(method):
        @wraps(method)
        def wrapped_method(self, *args, **kwargs):
            if not self.initialized:
                raise exception
            return method(self, *args, **kwargs)
        return wrapped_method
    return decorator