Lombok @Singular Annotation

@Builder Combined with @Singular annotation

it will provide single argument method for all Iterable, Collections, Map fields.

Example:

package sample.lombok;import java.util.Arrays;import java.util.List;import lombok.Builder;import lombok.Singular;import lombok.ToString;@Builder@ToStringpublic class Main {    public static void main(String[] args) {        MainBuilder builder = Main.builder()                                  .string("test")                                  .number(100)                                  .list("hoge")                                  .list("fuga")                                  .list(Arrays.asList("fizz", "buzz"));        Main m = builder.build();        System.out.println(m);    }    private String string;    private int number;    @Singular("list")    private List<String> list;}
Output:
Main(string=test, number=100, list=[hoge, fuga, fizz, buzz])

For more code check this: singular