Add key/value type annotations to cirq.PauliString.items() (#3790)
Add key/value type annotations to cirq.PauliString.items() (#3790)


quantumlib/Cirq,balopat/Cirq,quantumlib/Cirq,balopat/Cirq,balopat/Cirq,quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq