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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 to_json(self, drop_null=True, camel=False, indent=None, sort_keys=False):
 """Serialize self as JSON Args: drop_null: bool, default True. Remove 'empty' attributes. See to_dict. camel: bool, default True. Convert keys to camelCase. indent: int, default None. See json built-in. sort_keys: bool, default False. See json built-in. Return: str: object params. """

        return json.dumps(self.to_dict(drop_null, camel), indent=indent,
                          sort_keys=sort_keys)