code: public static String quote(String data) {
  		if (data == null) {
  			return "\"\"";
  		}
  		try {
  			JSONStringer stringer = new JSONStringer();
  			stringer.open(JSONStringer.Scope.NULL, "");
  			stringer.value(data);
  			stringer.close(JSONStringer.Scope.NULL, JSONStringer.Scope.NULL, "");
  			return stringer.toString();
  		}
  		catch (JSONException e) {
  			throw new AssertionError();
  		}
  	}
docs: Encodes {@code data} as a JSON string. This applies quotes and any necessary
  character escaping.
  @param data the string to encode. Null will be interpreted as an empty string.
  @return the quoted value