The proguard rule does not work on MI4 (Android 4.4)

[breezehou]

If use the following rule, it will be crashed on Android 4.4:
-dontwarn icepick.** -keep class icepick.** { *; } -keep class **$$Icepick { *; } -keepclasseswithmembernames class * { @icepick.* <fields>; } -keepnames class * { @icepick.State *;}
Crash logs (I used apache commons lib in my project):
java.lang.NoSuchMethodError: org.apache.commons.lang3.StringUtils.a ... ...
If I removed <-keepnames class * { @Icepick.State *;}> line, it works, I don't know why.