Help with rogue routine please dev

[Slayor]

is this line correct..

Spell.Cast("Trickster_Mechanic_Stealth", ent => ent as NWUnit, ent => !(ent as NWUnit).Character.HasBuff("Trickster_Mechanic_Stealth")), //null, ext => (ext as NWUnit).Distance <= 55f, ent => (ent as NWUnit).Position),