Template instances
A template instance object represents an occurrence of a template in the document. It can be used to access the DOM and it can be assigned properties that persist as the template is reactively updated.
Template instance objects are found as the value of this in the onCreated, onRendered, and onDestroyed template callbacks, and as an argument to event handlers. You can access the current template instance from helpers using Template.instance().
In addition to the properties a