Need help creating a recipe using minetweaker

Right now I am attempting to make a recipe for dragon eggs using minetweaker, however i keep getting the message

ERROR: recipe.zs:4 > a method available but none matches the parameters (minetweaker.item.IItemstack, minetweaker.item.IIngredient[], any[])

Here is my script

val core = draconicevolution:awakened_core;

val degg = minecraft:dragon_egg;

val egg = minecraft:egg;

recipes.addShaped(degg,

[null, [core], null],

[[core], [egg], [core],

[null, [core], null]]);

I am not sure what is wrong with it, any help is appreciated.