build/web/c0.js
function insertChildAt(parentNode, childNode, index) {
  // By exploiting arrays returning `undefined` for an undefined index, we can
  // rely exclusively on `insertBefore(node, null)` instead of also using
  // `appendChild(node)`. However, using `undefined` is not allowed by all
  // browsers so we must replace it with `null`.
  parentNode.insertBefore(
    childNode,
    parentNode.childNodes[index] || null
  );
}
function insertChildAt(parentNode, childNode, index) {
  // By exploiting arrays returning `undefined` for an undefined index, we can
  // rely exclusively on `insertBefore(node, null)` instead of also using
  // `appendChild(node)`. However, using `undefined` is not allowed by all
  // browsers so we must replace it with `null`.
  parentNode.insertBefore(
    childNode,
    parentNode.childNodes[index] || null
  );
}
function insertChildAt ( parentNode , childNode , index ) { // By exploiting arrays returning `undefined` for an undefined index, we can // rely exclusively on `insertBefore(node, null)` instead of also using // `appendChild(node)`. However, using `undefined` is not allowed by all // browsers so we must replace it with `null`. parentNode . insertBefore ( childNode , parentNode . childNodes [ index ] || null ) ; }
Inserts `childNode` as a child of `parentNode` at the `index`.

@param {DOMElement} parentNode Parent node in which to insert.
@param {DOMElement} childNode Child node to insert.
@param {number} index Index at which to insert the child.
@internal
Inserts childNode as a child of parentNode at the index .