Helper function used in memoization of an HTML Node.

memoizeNode.js

module.exports = function memoizeNode(node) {
 var element
 var placeholder
 var mounted = false
   return function render() {
    if(!element) {
      element = node
      mounted = true
      return element
    }      
    else if (!mounted) {
      mounted = true
      return element
    }
    else {
      placeholder = html`<template></template>`
      placeholder.isSameNode = function(el) {
        el.isSameNode(element)
      }
      return placeholder
    }
  }
}

This snippet was extrapolated from the code found Here