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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_single_node(self) -> yaml.Node: """Hook used when loading a single document. This is the hook we use to hook yatiml into ruamel.yaml. It is \ called by the yaml libray when the user uses load() to load a \ YAML document. Returns: A processed node representing the document. """

        node = super().get_single_node()
        if node is not None:
            node = self.__process_node(node, type(self).document_type)
        return node