code: public String
  getErrorString() {
  	checkDone();
  	if (error != null)
  		return error;
  	switch (result) {
  		case SUCCESSFUL:	return "successful";
  		case UNRECOVERABLE:	return "unrecoverable error";
  		case TRY_AGAIN:		return "try again";
  		case HOST_NOT_FOUND:	return "host not found";
  		case TYPE_NOT_FOUND:	return "type not found";
  	}
  	throw new IllegalStateException("unknown result");
  }
docs: Returns an error string describing the result code of this lookup.
  @return A string, which may either directly correspond the result code
  or be more specific.
  @throws IllegalStateException The lookup has not completed.