-keep public class * {
    public protected *;
}

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepparameternames
-renamesourcefileattribute SourceFile
-keepattributes Exceptions,InnerClasses,Signature,Deprecated,SourceFile,LineNumberTable,EnclosingMethod
-keepclassmembers enum * { *; }