renderElement.js

function renderElement(page, selector) {
	var prevClipRect = page.clipRect;

	page.clipRect = page.evaluate(function(selector) {
		return document.querySelector(selector).getBoundingClientRect();
	}, selector);


	var pic = page.renderBase64('png');
	page.clipRect = prevClipRect;
	return pic;
}

if (module && module.exports) module.exports = renderElement;