@Override
    public ConfigDiff resume(TaskSource taskSource, Schema schema, int taskCount, Control control) {
        control.run(taskSource, schema, taskCount);
        return Exec.newConfigDiff();
    }
This plugin is used for TestingEmbulk.InputBuilder.preview().
embulk-junit4/src/main/java/org/embulk/test/PreviewResultInputPlugin.java