Which Design Pattern should I use in this scenario

I have XMLUtil Class and CSVUtil Class. Both of these Classes has different functions on its own and also has common functions.

XMLUtil.java has MethodA(),MethodB(),MethodC()

CSVUtil.java has MethodD(),MethodE(),MethodF(),MethodC()

Which design pattern should I follow and how should I go forward with this. Any example will be greatly appreciated.