Help, method in EntityLivingBase is not public

public class EntityLivingEventMoon {

private Random rand;

@SubscribeEvent
public void updateEntity(LivingUpdateEvent event) {
	boolean flag = event.entityLiving instanceof EntityPlayer && ((EntityPlayer)event.entityLiving).capabilities.disableDamage;

        if (event.entityLiving.isEntityAlive() && event.entityLiving.isInsideOfMaterial(Material.air))
        {
            if (!event.entityLiving.canBreatheUnderwater() && !event.entityLiving.isPotionActive(Potion.waterBreathing.id) && !flag)
            {
            	event.entityLiving.setAir(event.entityLiving.decreaseAirSupply(event.entityLiving.getAir())); //decreaseAirSupply is not visible

                if (event.entityLiving.getAir() == -20)
                {
                	event.entityLiving.setAir(0);

                    for (int i = 0; i < 8; ++i)
                    {
                        float f = this.rand.nextFloat() - this.rand.nextFloat();
                        float f1 = this.rand.nextFloat() - this.rand.nextFloat();
                        float f2 = this.rand.nextFloat() - this.rand.nextFloat();
                        event.entityLiving.worldObj.spawnParticle("bubble", event.entityLiving.posX + (double)f, event.entityLiving.posY + (double)f1, event.entityLiving.posZ + (double)f2, event.entityLiving.motionX, event.entityLiving.motionY, event.entityLiving.motionZ);
                    }

                    event.entityLiving.attackEntityFrom(DamageSource.drown, 2.0F);
                }
            }

            if (!event.entityLiving.worldObj.isRemote && event.entityLiving.isRiding() && event.entityLiving.ridingEntity != null && event.entityLiving.ridingEntity.shouldDismountInWater(event.entityLiving))
            {
            	event.entityLiving.mountEntity((Entity)null);
            }
        }
        else
        {
        	event.entityLiving.setAir(300);
        }


    }

}

protected int decreaseAirSupply(int air)
    {
        int j = EnchantmentHelper.getRespiration(this); //"this" needs to be entitylivingbase since i took the method straight from that class.
        return j > 0 && this.rand.nextInt(j + 1) > 0 ? air: air- 1;
    }