code: private ChocoConstraint build(Constraint cstr) throws SchedulerException {
          ChocoMapper mapper = params.getMapper();
          ChocoConstraint cc = mapper.get(cstr);
          if (cc == null) {
              throw new SchedulerModelingException(origin, "No implementation mapped to '" + cstr.getClass().getSimpleName() + "'");
          }
          return cc;
      }
docs: Build a sat constraint
  
  @param cstr the model-side constraint
  @return the solver-side constraint
  @throws SchedulerException if the process failed