code: public static void verifyCondition(@Nullable ErrorCollector errorCollector, @Nullable ValueRecorder recorder,
        @Nullable String text, int line, int column, @Nullable Object message, @Nullable Object condition) {
      if (!GroovyRuntimeUtil.isTruthy(condition)) {
        final ConditionNotSatisfiedError conditionNotSatisfiedError = new ConditionNotSatisfiedError(
          new Condition(getValues(recorder), text, TextPosition.create(line, column), messageToString(message), null, null));
        errorCollector.collectOrThrow(conditionNotSatisfiedError);
      }
    }
docs: condition can be null too, but not in the sense of "not available"