hollow/src/main/java/com/netflix/hollow/core/memory/ByteArrayOrdinalMap.java
private int rehashPreviouslyAddedData(long key) {
        long position = key & POINTER_MASK;

        int sizeOfData = VarInt.readVInt(byteData.getUnderlyingArray(), position);
        position += VarInt.sizeOfVInt(sizeOfData);

        return HashCodes.hashCode(byteData.getUnderlyingArray(), position, sizeOfData);
    }
private int rehashPreviouslyAddedData(long key) {
        long position = key & POINTER_MASK;

        int sizeOfData = VarInt.readVInt(byteData.getUnderlyingArray(), position);
        position += VarInt.sizeOfVInt(sizeOfData);

        return HashCodes.hashCode(byteData.getUnderlyingArray(), position, sizeOfData);
    }
Get the hash code for the byte array pointed to by the specified key.