Returns how many slots are currently occupied by enemies in queue
Returns how much the production actually costs, scaled by the level
Returns how many slots are currently occupied by finished enemies
Returns how many slots are currently producing
Returns how many slots are remaining
Returns if the given enemy could get produced
Queues a new enemy to get produced
the enemy to produce
current in game time in seconds
the level of the enemy to produce
the uid of the spawned enemy later (already allocated now)
Takes all zombies which are done and returns them
Allows to produce and spawn zombies. Multiplayer only.