@Override
    public void mark(int limit) {
        markBuffer = new byte[tailSize];
        System.arraycopy(tailBuffer, 0, markBuffer, 0, tailSize);
        markIndex = currentIndex;
        markBytesRead = bytesRead;
    }
{@inheritDoc} This implementation saves the internal state including the
content of the tail buffer so that it can be restored when ''reset()'' is
called later.
tika-core/src/main/java/org/apache/tika/io/TailStream.java