code: public static ExecutionEntityImpl createWithEmptyRelationshipCollections() {
      ExecutionEntityImpl execution = new ExecutionEntityImpl();
      execution.executions = new ArrayList<ExecutionEntityImpl>(1);
      execution.tasks = new ArrayList<TaskEntity>(1);
      execution.variableInstances = new HashMap<String, VariableInstanceEntity>(1);
      execution.jobs = new ArrayList<JobEntity>(1);
      execution.timerJobs = new ArrayList<TimerJobEntity>(1);
      execution.eventSubscriptions = new ArrayList<EventSubscriptionEntity>(1);
      execution.identityLinks = new ArrayList<IdentityLinkEntity>(1);
      return execution;
    }
docs: Static factory method: to be used when a new execution is created for the very first time/
  Calling this will make sure no extra db fetches are needed later on, as all collections
  will be populated with empty collections. If they would be null, it would trigger
  a database fetch for those relationship entities.