code: public void addError(Message message, boolean fatal) throws CompilationFailedException {
          if (fatal) {
              addFatalError(message);
          }
          else {
              addError(message);
          }
      }
docs: Adds an optionally-fatal error to the message set.
  The message is not required to have a source line and column specified, but it is best practice to try
  and include that information.
  @param fatal
  if true then then processing will stop