private void AddMembershipRow(DbDataReader reader)
{
var containerId = reader.GetInt32(0);
var userId = reader.GetInt32(1);
var containerType = reader.GetString(2);
if (!membership.ContainsKey(userId))
membership.Add(userId, new List<int>());
if (!membership[userId].Contains(containerId))
membership[userId].Add(containerId);
}