@Override
                public void onCompletion(GetBlobResult getBlobResult, Exception exception) {
                  if (getBlobResult != null) {
                    exceptionToReturn.set(new IllegalStateException(
                        "Get of a deleted blob " + blobId + " should have failed with " + RouterErrorCode.BlobDeleted));
                  } else {
                    if (exception != null) {
                      exceptionToReturn.set(exception);
                    }
                  }
                }
{@inheritDoc}
Request to delete the blob from the server directly pertaining to the {@code blobId} passed in and verify that
the subsequent get fails with {@link RouterErrorCode#BlobDeleted}
@param blobId the blobId the of that blob that needs to be fetched
@param expectedErrorCode the expected error code for the Delete call
@param callback the {@link Callback} that will be called on completion
@param metricsCollector the {@link MetricsCollector} to collect and report metrics
ambry-tools/src/main/java/com/github/ambry/tools/admin/ConcurrencyTestTool.java