docs: public synchronized static String mask(String inString) {
          String outString = null;
  
          if (inString != null) {
              char[] outStringBuffer = new char[inString.length()];
  
              for (int i = 0; i < inString.length(); i++) {
                  outStringBuffer[i] = '*';
              }
  
              outString = new String(outStringBuffer);
          }
  
          return outString;
      }