return null;
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.internal.CommonServerMessageBlockRequest#allowChain(jcifs.internal.CommonServerMessageBlockRequest)
     */
    @Override
    public boolean allowChain ( CommonServerMessageBlockRequest next ) {
        return false;
    }


    /**
     * {@inheritDoc}
     *

        return getAsyncId() != 0;
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.internal.CommonServerMessageBlockRequest#allowChain(jcifs.internal.CommonServerMessageBlockRequest)
     */
    @Override
    public boolean allowChain ( CommonServerMessageBlockRequest next ) {
        return getConfig().isAllowCompound(getClass().getSimpleName()) && getConfig().isAllowCompound(next.getClass().getSimpleName());

    /**
     * @return create cancel request
     */
    CommonServerMessageBlockRequest createCancel ();


    /**
     * @param next
     * @return whether to allow chaining
     */
    boolean allowChain ( CommonServerMessageBlockRequest next );


    /**
     * @param t
     */
    void setTid ( int t );


    /**
     * 
     * @return custom response timeout for this request
     */

        return null;
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.internal.CommonServerMessageBlockRequest#allowChain(jcifs.internal.CommonServerMessageBlockRequest)
     */
    @Override
    public boolean allowChain ( CommonServerMessageBlockRequest next ) {
        return false;
    }


    /**
     * {@inheritDoc}
     *

                        String.format("%s costs %d avail %d (%s)", chain.getClass().getName(), cost, this.credits.availablePermits(), this.name));
                }
                if ( ( next == null || chain.allowChain(next) ) && totalSize + size < maxSize && this.credits.tryAcquire(cost) ) {
                    totalSize += size;
                    last = chain;
                    chain = next;
                }