 When `true`, events handled by declarative event listeners
       *   (`on-event="handler"`) will be decorated with a `model` property pointing
       *   to the template instance that stamped it.  It will also be returned
       *   from `instance.parentModel` in cases where template instance nesting
       *   causes an inner model to shadow an outer model.
       *
       * Note that the class returned from `templatize` is generated only once
       * for a given `<template>` using `options` from the fi