keep only function names when obfuscation for proguard

I use proguard for obfuscation. How can I keep only function names while obfuscation. class names must be obfuscated but function names.

if I use,

-keep class * {
     void somefunction();
}

and it keeps function of somefunction, but it doesnt change classes names.

But, I want to change classes names but somefunction

Answer

You can use -keepclassmembers or -keepclassmembernames.

Cfr. ProGuard manual > Usage > Overview of Keep Options