private Pointer getPointer() {
        if (ADDRESS_METHOD != null) {
            try {
                final long address = (long) ADDRESS_METHOD.invoke(this.buffer);
                Pointer pointer = new Pointer(address);
                return pointer;
            } catch (Throwable t) {
                // NOPMD
            }
        }
        return null;
    }
return true when this segment file is blank that we don't write any data into it.
@return
jraft-core/src/main/java/com/alipay/sofa/jraft/storage/log/SegmentFile.java