public int getLength() {
        if (this.bytes == null) {
            throw new IllegalStateException(
                    "Uninitialiized. Null constructor " + "called w/o accompaying readFields invocation");
        }
        return this.length;
    }
Returns the number of valid bytes in the buffer
stroom-bytebuffer/src/main/java/stroom/bytebuffer/hbase/Bytes.java