code: protected static String generateSecret(Random random) {
          
          String charsetForSecret = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
          
          StringBuilder stringBuilder = new StringBuilder(64);
          
          for (int i = 0; i < 64; i++) {
              
              int charToPoPickFromCharset = random.nextInt(charsetForSecret.length());            
              stringBuilder.append(charsetForSecret.charAt(charToPoPickFromCharset));
              
          }
  
          return stringBuilder.toString(); 
          
      }
docs: !!!! Only for testing purposes !!!!
  
  Usually you want to use {@link SecretGenerator#generateSecret()}
  
  @param random the random generator to use. Usually new Random(), but for testing you can
  use a predefined seed.
  @return A String suitable as random secret for eg signing a session.