code: function prepareEmbed(embedID) {
    var embed = document.getElementById(embedID);
  
    if (!isEmbeddedVideo(embed)) {
      throw new Error('embed must be an iframe');
    }
  
    enableAPIControl(embed);
  }
docs: Prepare an iframe for API control.
  
  Embedded Vimeo videos require `api` & `player_id`
  parameters set to be controlled.
  
  @param {String} embedID - id of iframe to prepare