super(builder, config, parent, child, context);
this.format = getConfigs().getString(config, "format");
List<String> argList = getConfigs().getStringList(config, "args", Collections.<String>emptyList());
this.expressions = new FieldExpression[argList.size()];
for (int i = 0; i < argList.size(); i++) {
this.expressions[i] = new FieldExpression(argList.get(i), getConfig());
}
validateArguments();
}