def set_image(self, **kwargs):
        """
        set image of embed
        :keyword url: source url of image (only supports http(s) and attachments)
        :keyword proxy_url: a proxied url of the image
        :keyword height: height of image
        :keyword width: width of image
        """
        self.image = {
            'url': kwargs.get('url'),
            'proxy_url': kwargs.get('proxy_url'),
            'height': kwargs.get('height'),
            'width': kwargs.get('width'),
        }
set image of embed
        :keyword url: source url of image (only supports http(s) and attachments)
        :keyword proxy_url: a proxied url of the image
        :keyword height: height of image
        :keyword width: width of image