src/main/java/org/nustaq/serialization/FSTObjectOutput.java
public void resetForReUse( OutputStream out ) {
        if ( closed )
            throw new RuntimeException("Can't reuse closed stream");
        getCodec().reset(null);
        if ( out != null ) {
            getCodec().setOutstream(out);
        }
        objects.clearForWrite(conf);
    }
public void resetForReUse( OutputStream out ) {
        if ( closed )
            throw new RuntimeException("Can't reuse closed stream");
        getCodec().reset(null);
        if ( out != null ) {
            getCodec().setOutstream(out);
        }
        objects.clearForWrite(conf);
    }
if out == null => automatically create/reuse a bytebuffer

@param out