阅读下列代码 import java.io.*; public class Example{ public static void main(String[] args) throws Exception { OutputStream out = new FileOutputStream("itcast.txt ", true); String str = "欢迎你!"; byte[] b = str.getBytes(); for (int i = 0; i < b.length; i++) { out.______(b[i]); } out.close(); } } 请说出下划线上,填写的方法名称。