@Override
    public void testAndAssert(RouterErrorCode expectedError) throws Exception {
      if (expectedError == null) {
        getAndAssertSuccess();
      } else {
        GetBlobOperation op = createOperationAndComplete(null);
        assertFailureAndCheckErrorCode(op, expectedError);
      }
    }
A checker that either asserts that a get operation succeeds or returns the specified error code.P
ambry-router/src/test/java/com/github/ambry/router/GetBlobOperationTest.java