Given a class Repetition：<br /> 1.package utils；<br /> 2.<br /> 3.public class Repetition{<br /> 4.public static String twice（Strings）{returns+s；}<br /> 5.}<br /> and given another class Demo：<br /> 1.//insert code here2.<br /> 3.public class Demo{<br /> 4.public static void main（String[]args）{<br /> 5.System.out.println（twice（"pizza"））；<br /> 6.}<br /> 7.}<br /> Which code should be inserted at line 1 of Demo.java to compile and run Demo to print&ldquo;pizzapizza&rdquo;？（）