docs: public static String getSimpleName(Class<?> type, String separator) {
          final StringBuilder buf = new StringBuilder();
          Class<?> c = type;
          while (c != null) {
              if (buf.length() > 0 && separator != null) {
                  buf.insert(0, separator);
              }
              buf.insert(0, c.getSimpleName());
              c = c.getEnclosingClass();
          }
          return buf.toString();
      }