encountered idle timeout earlier?").</li>
<li>Once the handler is called, its signature is similar (<code>Error_code</code>, <code>size_t</code> of bytes received) but with one added arg, <code>const Blob_mutable&amp; target_payload_blob</code>, which is simply a copy of the light-weight object returned per preceding bullet point.<ul>
<li>It is possible <code>target_payload_blob_func()</code> is never called; in this case the error code shall be truthy, and the reported size received shall be 0. In this cas