@Override
    public void execute(
            final HttpRequest request,
            final AsyncEntityProducer entityProducer,
            final AsyncExecChain.Scope scope,
            final AsyncExecChain chain,
            final AsyncExecCallback asyncExecCallback) throws HttpException, IOException {
        final State state = new State();
        state.retrying = false;
        internalExecute(state, request, entityProducer, scope, chain, asyncExecCallback);
    }
Request executor in the asynchronous request execution chain that is
responsible for making a decision whether a request that failed due to
an I/O exception or received a specific response from the target server should
be re-executed.
<p>
Further responsibilities such as communication with the opposite
endpoint is delegated to the next executor in the request execution
chain.
</p>
<p>
If this handler is active, pay particular attention to the placement
of other handlers within the handler chain relative to the retry handler.
Use {@link ChainElement#RETRY} as name when referring to this handler.
</p>
<p>
If a custom handler is placed <b>before</b> the retry handler, the handler will
see the initial request and the final outcome after the last retry. Elapsed time
will account for any delays imposed by the retry handler.
</p>

<p>
A custom handler which is placed <b>after</b> the retry handler will be invoked for
each individual retry. Elapsed time will measure each individual http request,
without the delay imposed by the retry handler.
</p>

@since 5.0
httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncHttpRequestRetryExec.java