/// <summary>Toggle the active state of the <see cref="IHostfileEntry"/> with the specified <paramref name="uniqueIdentifier"/>.</summary>
        /// <param name="uniqueIdentifier">The unique identifier of an <see cref="IHostfileEntry"/> object.</param>
        /// <returns>True if the active state of the <see cref="IHostfileEntry"/> with the specified <paramref name="uniqueIdentifier"/> was successfully toggled; otherwise false.</returns>
        public bool ToggleActiveStateObsolete(Guid uniqueIdentifier)
        {
            IHostfileEntry item = this.GetElementBy(uniqueIdentifier);

            if (item != null && item.IsActivatable)
            {
                ActivatableHostfileEntry activatableItem = item as ActivatableHostfileEntry;
                if (activatableItem != null)
                {
                    bool currentState = activatableItem.IsActive;
                    activatableItem.IsActive = !currentState;
                    bool newState = activatableItem.IsActive;

                    return(currentState != newState);
                }
            }

            return(false);
        }
        /// <summary>Toggle the active state of the specified <paramref name="activatableHostfileEntry"/>.</summary>
        /// <param name="activatableHostfileEntry">A <see cref="IHostfileEntry"/> object.</param>
        /// <returns>True if the active state of the specified <see cref="IHostfileEntry"/> was successfully toggled; otherwise false.</returns>
        public bool ToggleActiveState(ActivatableHostfileEntry activatableHostfileEntry)
        {
            /* abort if parameter is null */
            if (activatableHostfileEntry == null)
            {
                return false;
            }

            /* toggle host status */
            if (activatableHostfileEntry.HasParent)
            {
                activatableHostfileEntry.ToggleActiveState();
                return true;
            }

            /* toggle group status */
            return this.HostFileInstance.ToggleActiveState(activatableHostfileEntry.UniqueIdentifier);
        }