  RouterTest() : RouterTestBase(false, false, false, Protobuf::RepeatedPtrField<std::string>{}) {
    EXPECT_CALL(callbacks_, activeSpan()).WillRepeatedly(ReturnRef(span_));
  };
  RouterTest() : RouterTestBase(false, false, false, Protobuf::RepeatedPtrField<std::string>{}) {
    EXPECT_CALL(callbacks_, activeSpan()).WillRepeatedly(ReturnRef(span_));
  };