private String getRandomString() {
    int leftLimit = 97; // letter 'a'
    int rightLimit = 122; // letter 'z'
    int maxLength = 100;

    String generatedString = random.ints(leftLimit, rightLimit + 1)
        .limit(random.nextInt(maxLength))
        .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
        .toString();

    return generatedString;
  }
Make sure that the histograms can record the key value size and we can use a
{@link MetricsVisitor} to get access to the value store in the histograms
samza-test/src/test/java/org/apache/samza/storage/kv/TestKeyValueSizeHistogramMetric.java