code: public Object nextEntity(@SuppressWarnings("unused") char ampersand) throws JSONException {
          StringBuilder sb = new StringBuilder();
          for (;;) {
              char c = next();
              if (Character.isLetterOrDigit(c) || c == '#') {
                  sb.append(Character.toLowerCase(c));
              } else if (c == ';') {
                  break;
              } else {
                  throw syntaxError("Missing ';' in XML entity: &" + sb);
              }
          }
          String string = sb.toString();
          return unescapeEntity(string);
      }
docs: Return the next entity. These entities are translated to Characters:
  <code>&amp;  &apos;  &gt;  &lt;  &quot;</code>.
  @param ampersand An ampersand character.
  @return  A Character or an entity String if the entity is not recognized.
  @throws JSONException If missing ';' in XML entity.