_upgrade.description">Description</a>
      </h5>
<p>
        This function returns <code class="computeroutput"><span class="keyword">true</span></code> when
        the passed HTTP Request indicates a WebSocket Upgrade. It does not validate
        the contents of the fields: it just trivially accepts requests which could
        only possibly be a valid or invalid WebSocket Upgrade message. Callers who
        wish to manually read HTTP requests in their server implementation can use
        this functio