internal void Merge(IEnumerable <Mission> additional)
{
foreach (var m in additional)
{
var existing = MissionList.FirstOrDefault((x) => x.ID == m.ID);
if (existing != null)
{
existing.UnlockTime = m.UnlockTime;
// Refresh cycle will trigger PropertyChanged
}
else
{
MissionList.Add(m);
}
}
}
