<p>A request Header can be updated dynamically using the <code>@Header</code> annotation. A corresponding parameter must be provided to the <code>@Header</code>. If the value is null, the header will be omitted. Otherwise, <code>toString</code> will be called on the value, and the result used.</p>
<p>Headers that need to be added to every request can be specified using an <ahref="https://github.com/square/okhttp/wiki/Interceptors">OkHttp interceptor</a>.