code: public static Properties sanitize(Properties properties) {
          // convert any non-String keys/values to Strings
          Properties sanitizedEntries = new Properties();
          for (Iterator<?> itr = properties.entrySet().iterator(); itr.hasNext(); ) {
              Map.Entry entry = (Map.Entry) itr.next();
              if (!(entry.getKey() instanceof String)) {
                  String key = sanitize(entry.getKey());
                  if (!properties.containsKey(key)) {
                      sanitizedEntries.setProperty(key, sanitize(entry.getValue()));
                  }
                  itr.remove();
              } else if (!(entry.getValue() instanceof String)) {
                  entry.setValue(sanitize(entry.getValue()));
              }
          }
          properties.putAll(sanitizedEntries);
          return properties;
      }
docs: Utility method to sanitize the set of instructions.
  
  @param properties the current instructions
  @return the new set of instructions