An IPotionEffect is an IPotion that also has a duration and an amplifier (strength) parameter.
You can get them from an IPotion object.

It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.potions.IPotionEffect;

ZenGetter	类型
ZenGetter duration	类型 int
ZenGetter potion	类型 IPotion
ZenGetter doesShowParticles	类型 bool
ZenGetter amplifier	类型 int
ZenGetter curativeItems	类型 List<IItemStack>
ZenGetter effectName	类型 string
ZenGetter isAmbient	类型 bool
ZenGetter isPotionDurationMax (also a ZenSetter)	类型 bool

Uses an IItemStack.
Returns a bool

ZenScript
 Copy
isCurativeItem(IItemStack item);

Uses an IEntity or any of its subclasses (e.g. IPlayer).
Returns void (nothing).

ZenScript
 Copy
performEffect(IEntity Entity);