src/main/java/org/nustaq/offheap/bytez/malloc/MMFBytez.java
public void _setMMFData(File file, FileChannel fileChannel,Cleaner cleaner) {
        this.file = file; this.fileChannel = fileChannel; this.cleaner = cleaner;
    }
public void _setMMFData(File file, FileChannel fileChannel,Cleaner cleaner) {
        this.file = file; this.fileChannel = fileChannel; this.cleaner = cleaner;
    }
hack to update underlying file in slices handed out to app