/// <summary>
        /// Gets the recipients of the specified exit event
        /// </summary>
        /// <param name="exitEventRecipients">A list of reference attributes to obtain recipients from</param>
        /// <returns>A list of MAObjectHologram to send the specified exit event to</returns>
        private IList <MAObjectHologram> GetEventRecipientsFromAttributes(MAObjectHologram hologram)
        {
            List <MAObjectHologram> recipients = new List <MAObjectHologram>();

            foreach (AcmaSchemaAttribute recipientAttribute in this.Recipients)
            {
                AttributeValues values = hologram.GetAttributeValues(recipientAttribute);

                if (!values.IsEmptyOrNull)
                {
                    foreach (AttributeValue value in values)
                    {
                        MAObjectHologram recipient = ActiveConfig.DB.GetMAObjectOrDefault(value.ValueGuid);
                        if (recipient == null)
                        {
                            hologram.MarkMissingReference(value.ValueGuid, recipientAttribute);
                        }
                        else
                        {
                            recipients.Add(recipient);
                        }
                    }
                }
            }

            return(recipients);
        }