code: package org.optsol.project_scheduling.mrcpsp.ooe.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.stream.Collectors;
  import org.optsol.jdecor.core.AbstractConstraintManager;
  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.ooe.variables.DecisionVars_Ooe;
  
  public class OOE_e_AtLeastOneEvent<CONST extends
      IConstants_E & IConstants_A & IConstants_M_i>
      extends AbstractOrtoolsConstraintManager<CONST> {
  
    public OOE_e_AtLeastOneEvent() {
      super("i");
    }
  
    @Override
    protected Collection<ConstraintKey> createKeys(CONST constants) {
      return constants.get_A().stream()
          .map(ConstraintKey::new)
          .collect(Collectors.toSet());
    }
  
    @Override
    protected void configureConstraint(
        MPConstraint constraint,
        CONST constants,
        AbstractVariableManager<MPSolver, MPVariable> variables,
        AbstractConstraintManager<MPSolver, CONST, MPVariable, MPConstraint>.ConstraintKey constraintKey)
        throws Exception {
  
      int i = constraintKey.get("i");
  
      constraint.setLb(1.);
  
      for (int m : constants.get_M_i(i)) {
        for (int e : constants.get_E()) {
          if (e != constants.get_card_A()) {
            constraint.setCoefficient(variables.getVar(DecisionVars_Ooe.z, i, m, e), 1.);
          }
        }
      }
    }
  }
  