code: def _simulator_iterator(
          self,
          circuit: circuits.Circuit,
          param_resolver: study.ParamResolver,
          qubit_order: ops.QubitOrderOrList,
          initial_state: Any,
      ) -> Iterator:
          
          raise NotImplementedError()
docs: 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.