public void bind(
     List<Stakeholder> stakeholders, List<FunctionalRequirement> functionalRequirements) {
   for (Stakeholder sh : stakeholders) {
     if (sh.getId().equals(stakeholderId)) this.stakeholder = sh;
   }
   for (FunctionalRequirement fr : functionalRequirements) {
     if (fr.getId().equals(functionalRequirementID)) {
       this.functionalRequirement = fr;
       fr.getAssociations().add(this);
     }
   }
 }
 @Override
 public String toString() {
   return "From: "
       + stakeholder.getName()
       + " to: "
       + functionalRequirement.getName()
       + " with probability: "
       + probability;
 }