@Test
  public void testBlobNotFoundCase() throws Exception {
    mockServerLayout.getMockServers()
        .forEach(server -> server.setServerErrorForAllRequests(ServerErrorCode.BlobNotFound));
    assertOperationFailure(RouterErrorCode.BlobDoesNotExist);
    // Blob is created by putBlob function so the local datacenter will be the origin datecenter.
    // It requires at least 2 Blob_Not_Found responses to terminate the operation.
    Assert.assertTrue("Must have attempted sending at least 3 requests to all originating dc replicas",
        correlationIdToGetOperation.size() >= 2);
  }
Test the case where every server returns Blob_Not_Found. All servers must have been contacted,
due to cross-colo proxying.
@throws Exception
ambry-router/src/test/java/com/github/ambry/router/GetBlobInfoOperationTest.java