code: function createCard(addressBook, options) {
    var objectUrl = _url2['default'].resolve(addressBook.url, options.filename);
    return webdav.createObject(objectUrl, options.data, options);
  }
docs: @param {dav.AddressBook} addressBook the address book to put the object on.
  @return {Promise} promise will resolve when the card has been created.
  
  Options:
  
  (String) data - vcard object.
  (String) filename - name for the address book vcf file.
  (dav.Sandbox) sandbox - optional request sandbox.
  (dav.Transport) xhr - request sender.