Merge pull request tensorflow#528 from quantumlib/u/maffoo/single-qubit-gate

Remove usage of deprecated `cirq.SingleQubitGate`

Author: 95-martin-orion

qsimcirq_tests/qsimcirq_test.py

@@ -19,7 +19,7 @@
 import qsimcirq
 
 
-class NoiseTrigger(cirq.SingleQubitGate):
+class NoiseTrigger(cirq.Gate):
     """A no-op gate with no _unitary_ method defined.
 
     Appending this gate to a circuit will force it to use qtrajectory, but the
@@ -29,6 +29,9 @@ class NoiseTrigger(cirq.SingleQubitGate):
     # def _mixture_(self):
     #   return ((1.0, np.asarray([1, 0, 0, 1])),)
 
+    def _num_qubits_(self) -> int:
+        return 1
+
     def _kraus_(self):
         return (np.asarray([1, 0, 0, 1]),)