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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 build(self):
 """Builds this controlled gate. :return: The controlled gate, defined by this object. :rtype: Program """

        self.defined_gates = set(STANDARD_GATE_NAMES)
        prog = self._recursive_builder(self.operation,
                                       self.gate_name,
                                       self.control_qubits,
                                       self.target_qubit)
        return prog