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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 serialize(self, data):
 """Serializes a dictionary into JSON. A dictionary with a single key can be passed and it can contain any structure. """

        if data is None:
            return None
        elif isinstance(data, dict):
            return serializer.Serializer().serialize(data)
        else:
            raise Exception(_("Unable to serialize object of type = '%s'") %
                            type(data))