code: public static InputStream fromURL(String url) throws IOException {
  		if(Strings.isValid(url)) {
  			return fromURL(URLFactory.makeURL(url));
  		}
  		return null;
  	}
docs: Reads a resource from an URL, specified as a string; since this class makes
  use of the URL factory, URLs may also represent resources in the class
  path, re (in the format "classpath:org/dihedron/resources/MyResource.png").
  
  @param url
  a string presenting an URL.
  @return
  an input stream to access the URL.
  @throws IOException
  if the URL is malformed or an error occurs opening the stream.