-keepattributes SourceFile,LineNumberTable
-keep public class * extends java.lang.Exception
-keeppackagenames
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses

# Keep GSON / JSON serialized members
-keepattributes *Annotation*
-keepclassmembers,allowobfuscation class * {
  @com.google.gson.annotations.SerializedName <fields>;
}