Unable to set value of SetPosition of Switchery from code- Angular4

Question

this.setPosition(labelParent) is not working in IE browser. Kindly Help.

Switchery.prototype.bindClick = function() {
  var parent = this.element.parentNode.tagName.toLowerCase()
    , labelParent = (parent === 'label') ? false : true;

  this.setPosition(labelParent);
  this.handleOnchange(this.element.checked);
};