DirStorageFactory4 has a field called rwsOK defined like this:
private static final boolean rwsOK = JVMInfo.JDK_ID >= JVMInfo.J2SE_142;
The only supported platform whose JVMInfo.JDK_ID is less than JVMInfo.J2SE_142, is FP/CDC. But DirStorageFactory4 is not used on FP/CDC because it depends on NIO. This means that the field will always have the value true, and it can be eliminated.