public String toString() {
    return "Field{" +
            "name='" + name + '\'' +
            ", alias='" + alias + '\'' +
            ", arguments=" + arguments +
            ", directives=" + directives + // <- used to be a List<Directive> now is DirectivesHolder
            ", selectionSet=" + selectionSet +
            '}';
}

SelectionSet{selections=[Field{name='description', alias='null', arguments=[], directives=graphql.language.NodeUtil$DirectivesHolder@64e8d216, selectionSet=null}]}