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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 new(self, val):
 """Add a new value to me. Args: val (LispVal):
 The value to be added. Returns: LispVal: The added value. Raises: ~parthial.errs.LimitationError: If I already contain the maximum number of elements. """

        if len(self.things) >= self.max_things:
            raise LimitationError('too many things')
        self.things.add(val)
        return val