loadImageFromURL(url, imageName) {
    if (!imageName || !url) {
      return Promise.reject(rejectMessages.invalidParameters);
    }

    return this.execute(commands.LOAD_IMAGE, imageName, url);
  }
Load image from url
@param {string} url - File url
@param {string} imageName - imageName
@returns {Promise<SizeChange, ErrorMsg>}
@example
imageEditor.loadImageFromURL('http://url/testImage.png', 'lena').then(result => {
     console.log('old : ' + result.oldWidth + ', ' + result.oldHeight);
     console.log('new : ' + result.newWidth + ', ' + result.newHeight);
});