src/Draggable/Plugins/Mirror/Mirror.js
function addMirrorClasses({mirror, mirrorClass, ...args}) {
  return withPromise((resolve) => {
    mirror.classList.add(mirrorClass);
    resolve({mirror, mirrorClass, ...args});
  });
}
function addMirrorClasses({mirror, mirrorClass, ...args}) {
  return withPromise((resolve) => {
    mirror.classList.add(mirrorClass);
    resolve({mirror, mirrorClass, ...args});
  });
}
function addMirrorClasses ( { mirror , mirrorClass , ... args } ) { return withPromise ( ( resolve ) => { mirror . classList . add ( mirrorClass ) ; resolve ( { mirror , mirrorClass , ... args } ) ; } ) ; }
Applys mirror class on mirror element
@param {Object} state
@param {HTMLElement} state.mirror
@param {String} state.mirrorClass
@return {Promise}
@private
Applys mirror class on mirror element