[Solved] [1.13.2] How to change drop chances for only one item?

I want to change drop chances for the vanilla sand block for only one item, for example, for the stick. But if i write this code, i change drop chances for all drops of the sand block:
 

		if ((event.getState().getBlock() instanceof BlockSand)) {
			event.getDrops().add(new ItemStack(Items.STICK, 1));
			event.setDropChance((float) 0.08);
		}

Edited June 1, 20196 yr by Tameet