Add random effect

Array.prototype.getRandomElement = function() {
	return this[Math.floor(Math.random() * this.length)];
}

const effects = [MobEffect.jump, MobEffect.blindness, MobEffect.regeneration, MobEffect.nightVision];
const minDur = 10;
const maxDur = 9999;

function useItem(x, y, z, itemId, blockId, side, itemDamage, blockDamage) {
	if (itemId==280) {
		const randomDuration = Math.floor(Math.random() * (maxDur - minDur + 1)) + minDur;
		const randomEffect = effects.getRandomElement();
		Entity.addEffect(getPlayerEnt(), randomEffect, randomDuration*20, 3);
	}
}