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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 base_url(klass, space_id, webhook_id, resource_id=None):
 """ Returns the URI for the webhook call. """


        return "spaces/{0}/webhooks/{1}/calls/{2}".format(
            space_id,
            webhook_id,
            resource_id if resource_id is not None else ''
        )