Readium sdk(android) apk build error with Proguard

[gibumkim]

If do not apply the proguard the error does not occur.

but

If me apply a proguard an error occurs.

!! proguard.cfg current modifications.

-keep class org.readium.sdk.* { ;}
-keepnames class org.readium.sdk.* {;}

-keep class .R
-keepclasseswithmembers class *.R$* {
public static ;
}

-keepclassmembers class * {
@android.webkit.JavascriptInterface ;
}

-keepclasseswithmembernames class * {
native ;
}

Is there something more to add?
Please confirm.

[gibumkim]

complete....

-keepnames class com.koushikdutta.async.** {;}
-keep class com.koushikdutta.async.* { *;}

-dontwarn android.support.v4.**
-keepnames class android.support.v4.** {;}
-keep class android.support.v4.* { *;}

-keepnames class org.readium.sdk.** {;}
-keep class org.readium.sdk.* { *;}

-keepclassmembers class *.R$ {
public static ;
}

-keep class *.R$

-keepattributes Annotation

-keepclassmembers class * {
@android.webkit.JavascriptInterface ;
}