code: package org.optsol.project_scheduling.mrcpsp.see.constraints;
  
  import com.google.ortools.linearsolver.MPConstraint;
  import com.google.ortools.linearsolver.MPSolver;
  import com.google.ortools.linearsolver.MPVariable;
  import java.util.Collection;
  import java.util.HashSet;
  import org.optsol.jdecor.core.AbstractVariableManager;
  import org.optsol.jdecor.ortools.AbstractOrtoolsConstraintManager;
  import org.optsol.project_scheduling.mrcpsp.constants.shared.events.IConstants_E;
  import org.optsol.project_scheduling.mrcpsp.constants.sub.IConstants_A;
  import org.optsol.project_scheduling.mrcpsp.constants.sub.IConstants_M_i;
  import org.optsol.project_scheduling.mrcpsp.constants.sub.IConstants_R;
  import org.optsol.project_scheduling.mrcpsp.constants.sub.IConstants_b_imk;
  import org.optsol.project_scheduling.mrcpsp.see.variables.DecisionVars_See;
  
  public class SEE_j_ResourceConservation<CONST extends IConstants_A & IConstants_E & IConstants_M_i & IConstants_R & IConstants_b_imk>
      extends AbstractOrtoolsConstraintManager<CONST> {
  
    public SEE_j_ResourceConservation() {
      super("e", "k");
    }
  
    @Override
    protected Collection<ConstraintKey> createKeys(CONST constants) {
      HashSet<ConstraintKey> indexes = new HashSet<>();
      for (int e : constants.get_E()) {
        if (e != 0 && e != constants.get_card_A()) {
          for (int k : constants.get_R()) {
            indexes.add(new ConstraintKey(e, k));
          }
        }
      }
      return indexes;
    }
  
    @Override
    protected void configureConstraint(
        MPConstraint constraint,
        CONST constants,
        AbstractVariableManager<MPSolver, MPVariable> variables,
        ConstraintKey index)
        throws Exception {
  
      int e = index.get("e");
      int k = index.get("k");
  
      constraint.setLb(0);
      constraint.setUb(0);
  
      constraint.setCoefficient(variables.getVar("r", e - 1, k), 1);
  
      for (int i : constants.get_A()) {
        for (int m : constants.get_M_i(i)) {
          constraint.setCoefficient(
              variables.getVar(DecisionVars_See.x, i, m, e),
              constants.get_b_imk(i, m, k));
        }
      }
  
      for (int i : constants.get_A()) {
        for (int m : constants.get_M_i(i)) {
          constraint.setCoefficient(
              variables.getVar(DecisionVars_See.y, i, m, e),
              -constants.get_b_imk(i, m, k));
        }
      }
  
      constraint.setCoefficient(variables.getVar("r", e, k), -1);
    }
  }