est that may be used to compute the retry time (in case the retry
 time information specified as a decimal interval in seconds).</dd>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>time when the request may be retried or <code>null</code> if there is no retry information available.</dd>
<dt><span class="throwsLabel">Throws:</span></dt>
<dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/NullPointerException.html?is-external=true" title="class or interface in java.lang">NullPointer