Where is "anchor" coming from on line 18 of content-selector?

[AshleyGrant]

https://github.com/aurelia/templating/blob/master/src/content-selector.js#L18

function findInsertionPoint(groups, index){
  var insertionPoint;

  while(!insertionPoint && index >= 0){
    insertionPoint = groups[index][0];
    index--;
  }

  // this line
  return insertionPoint || anchor;
}

This came up during @cmichaelgraham's work on TypeScript. Just wondering if the || anchor part should be removed? Line 88 https://github.com/aurelia/templating/blob/master/src/content-selector.js#L88

var anchor = findInsertionPoint(this.groups, index) || this.anchor,

Looks to be the only place this function is called, so we're curious.