/// <summary>
        /// Constuctor.
        /// </summary>
        /// <param name="viewModelStore">The store this view model belongs to.</param>
        /// <param name="referenceRSNode">ReferenceRSNode.</param>
        /// <param name="parent">Parent.</param>
        public DomainRoleViewModel(ViewModelStore viewModelStore, DomainRole role, DomainRelationshipViewModel parent)
            : base(viewModelStore, role.Relationship)
        {
            this.parentVM   = parent;
            this.domainRole = role;

            this.EventManager.GetEvent <ModelElementPropertyChangedEvent>().Subscribe(this.Role.Id, new Action <ElementPropertyChangedEventArgs>(OnRolePropertyChanged));
        }
        /// <summary>
        /// Constuctor.
        /// </summary>
        /// <param name="viewModelStore">The store this view model belongs to.</param>
        /// <param name="referenceRSNode">ReferenceRSNode.</param>
        /// <param name="parent">Parent.</param>
        public DomainRoleViewModel(ViewModelStore viewModelStore, DomainRole role, DomainRelationshipViewModel parent)
            : base(viewModelStore, role.Relationship)
        {
            this.parentVM = parent;
            this.domainRole = role;

            this.EventManager.GetEvent<ModelElementPropertyChangedEvent>().Subscribe(this.Role.Id, new Action<ElementPropertyChangedEventArgs>(OnRolePropertyChanged));
        }