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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 get_resource(self, resource_name):
 """Get a resource in a project. `resource_name` is the path of a resource in a project. It is the path of a resource relative to project root. Project root folder address is an empty string. If the resource does not exist a `exceptions.ResourceNotFound` exception would be raised. Use `get_file()` and `get_folder()` when you need to get nonexistent `Resource`\s. """

        path = self._get_resource_path(resource_name)
        if not os.path.exists(path):
            raise exceptions.ResourceNotFoundError(
                'Resource <%s> does not exist' % resource_name)
        elif os.path.isfile(path):
            return File(self, resource_name)
        elif os.path.isdir(path):
            return Folder(self, resource_name)
        else:
            raise exceptions.ResourceNotFoundError('Unknown resource '
                                                   + resource_name)