Add Max_Health

@Override
public Multimap < Attribute, AttributeModifier > getDefaultAttributeModifiers(EquipmentSlot equipmentSlot) {
    if (equipmentSlot == EquipmentSlot.MAINHAND) {
        ImmutableMultimap.Builder < Attribute, AttributeModifier > builder = ImmutableMultimap.builder();
        builder.putAll(super.getDefaultAttributeModifiers(equipmentSlot));
        // GENERATE A NEW UUID FROM https://www.uuidtools.com/minecraft HAVING THE SAME UUID ON MORE THAN ONE ITEM WILL MAKE PROBLEMS
        builder.put(Attributes.MAX_HEALTH, new AttributeModifier(UUID.fromString("e36329d9-3333-43a4-bfcf-d9d5f3bc0267"), "Item modifier", 2.0, AttributeModifier.Operation.ADDITION));
        return builder.build();
    }
    return super.getDefaultAttributeModifiers(equipmentSlot);
}



// ALSO ADD THESE IMPORTS!!
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.entity.ai.attributes.AttributeModifier;
import net.minecraft.world.entity.ai.attributes.Attribute;
import net.minecraft.world.entity.EquipmentSlot;

import java.util.UUID;

import com.google.common.collect.Multimap;
import com.google.common.collect.ImmutableMultimap;