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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 export_node(self, n) -> Dict[str, Union[str, List[str]]]: """ Return dict suitable for exporting to JSON. Args: n: A dict representing the data in a networkx AnalysisGraph node. Returns: The node dict with additional fields for name, units, dtype, and arguments. """

        node_dict = {
            "name": n[0],
            "units": _get_units(n[0]),
            "dtype": _get_dtype(n[0]),
            "arguments": list(self.predecessors(n[0])),
        }

        if not n[1].get("indicators") is None:
            for indicator in n[1]["indicators"].values():
                if "dataset" in indicator.__dict__:
                    del indicator.__dict__["dataset"]

            node_dict["indicators"] = [
                _process_datetime(indicator.__dict__)
                for indicator in n[1]["indicators"].values()
            ]
        else:
            node_dict["indicators"] = None

        return node_dict