code: public static Request request(String url, String... headers) {
  		Request.Builder request = new Request.Builder().url(url);
  		if (headers != null) {
  			int length = headers.length;
  			checkArgument(length % 2 == 0, "headers length must be a multiple of two");
  			for (int i = 0; i < length; i += 2) {
  				request.addHeader(headers[i], headers[i + 1]);
  			}
  		}
  		return request.build();
  	}
docs: Get a GET request for the URL and headers.
  
  @param headers
  length must be a multiple of two: {@code String name, String value, ...}