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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 _simulator_iterator( self, circuit: circuits.Circuit, param_resolver: study.ParamResolver, qubit_order: ops.QubitOrderOrList, initial_state: Any, ) -> Iterator: """Iterator over StepResult from Moments of a Circuit. Args: circuit: The circuit to simulate. param_resolver: A ParamResolver for determining values of Symbols. qubit_order: Determines the canonical ordering of the qubits. This is often used in specifying the initial state, i.e. the ordering of the computational basis states. initial_state: The initial state for the simulation. The form of this state depends on the simulation implementation. See documentation of the implementing class for details. Yields: StepResults from simulating a Moment of the Circuit. """

        raise NotImplementedError()