docs/lib/mithril.js
function updateStyle(element, old, style) {
		if (old === style) element.style.cssText = "", old = null
		if (style == null) element.style.cssText = ""
		else if (typeof style === "string") element.style.cssText = style
		else {
			if (typeof old === "string") element.style.cssText = ""
			for (var key2 in style) {
				element.style[key2] = style[key2]
			}
			if (old != null && typeof old !== "string") {
				for (var key2 in old) {
					if (!(key2 in style)) element.style[key2] = ""
				}
			}
		}
	}
function updateStyle(element, old, style) {
		if (old === style) element.style.cssText = "", old = null
		if (style == null) element.style.cssText = ""
		else if (typeof style === "string") element.style.cssText = style
		else {
			if (typeof old === "string") element.style.cssText = ""
			for (var key2 in style) {
				element.style[key2] = style[key2]
			}
			if (old != null && typeof old !== "string") {
				for (var key2 in old) {
					if (!(key2 in style)) element.style[key2] = ""
				}
			}
		}
	}
style