I've set up an application key, shape, service, and thing, and am ready to update the thing using REST calls. However, I will have potentially thousands of things of the exact same type, though each with a unique serial number. What I'm unclear on is how I manage this in Thingworx. Does the thing identifier account for this, and if so, how? Also, when updating values, how do I specify which 'thing' the updates apply to?