code: public static void assertTrue(@Nullable final String message, final boolean condition) {
      if (!condition) {
        final AssertionError error = new AssertionError(GetUtils.ensureNonNull(message, "Condition must be TRUE"));
        MetaErrorListeners.fireError(error.getMessage(), error);
        throw error;
      }
    }
docs: Assert condition flag is TRUE. GEL will be notified about error.
  
  @param message   message describing situation
  @param condition condition which must be true
  @throws AssertionError if the condition is not true
  @since 1.0