Function renderStatic

static/vuejs/vue.runtime.esm.js:3499–3516

* Runtime helper for rendering static trees.

(
  index,
  isInFor
)

 * Runtime helper for rendering static trees.
 */
function renderStatic (
  index,
  isInFor
) {
  var tree = this._staticTrees[index];
  // if has already-rendered static tree and not inside v-for,
  // we can reuse the same tree by doing a shallow clone.
  if (tree && !isInFor) {
    return Array.isArray(tree)
      ? cloneVNodes(tree)
      : cloneVNode(tree)
  }
  // otherwise, render a fresh tree.
  tree = this._staticTrees[index] =
    this.$options.staticRenderFns[index].call(this._renderProxy);
  markStatic(tree, ("__static__" + index), false);
  return tree
}

/**
 * Runtime helper for v-once.