public static String getRandomKey(int size) {
    StringBuilder sb = new StringBuilder();
    while (sb.length() < size) {
      sb.append(Integer.toHexString(TestUtils.RANDOM.nextInt()));
    }
    sb.setLength(size);
    return sb.toString();
  }
Generates and returns a random Hex String of the specified size
@param size expected key hex string size
@return the hex string thus generated
ambry-test-utils/src/main/java/com/github/ambry/utils/TestUtils.java