code: package org.optsol.project_scheduling.mrcpsp.constants.sub;
  
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Collectors;
  import java.util.stream.IntStream;
  
  public interface IConstants_B_k {
  
    Map<Integer, Integer> get_B_k();
  
    default int get_B_k(int k) {
      if (get_B_k().get(k) == null) {
        System.out.println("stop");
      }
      return get_B_k().get(k);
    }
  
    default List<Integer> get_B_k_asList(int k) {
      //B_k assumed integer-valued
      return IntStream.rangeClosed(1, get_B_k(k)).boxed().collect(Collectors.toList());
    }
  }
  