public void append(final byte[] alreadyEncoded) throws java.io.IOException {
        if (alreadyEncoded.length > 0) {
            append(alreadyEncoded, 0, alreadyEncoded.length);
        }
    }
Data store for AbstractByteWriter. Tested in unit tests for ByteWriter.

@author Steinar Knutsen
vespajlib/src/main/java/com/yahoo/io/BufferChain.java