Type 'Headers' has no properties in common with type 'RequestOptionsArgs'? : <p>I just made two important upgrades to our Angular 4 application and build tools:</p>

<ol>
<li><em>@angular/core</em> <code>^4.1.3</code> => <code>^4.2.4</code> (and /http, /forms, etc)</li>
<li><em>tslint</em> <code>^5.3.2</code> => <code>^5.4.3</code></li>
</ol>

<p>I have a Service which declares options like so:</p>

<pre><code>@Injectable()
export class WorkOrderService {

    private headers: Headers = new Headers({ 'Content-Type': 'application/json' });
    private options: RequestOptions = new RequestOptions(this.headers);

    constructor(private http: Http) {}

    /* Methods ... */
}
</code></pre>

<p>The above now no longer validates tslint, throwing the following error:</p>

<blockquote>
  <p>error TS2559: Type 'Headers' has no properties in common with type 'RequestOptionsArgs'.</p>
</blockquote>

<p>The source (@angular/http <code>interface.d.ts:43</code>) clearly allows for <code>Headers</code> as a <code>RequestOptionsArgs</code>:</p>

<pre><code>/**
 * Interface for options to construct a RequestOptions, based on
 * [RequestInit](https://fetch.spec.whatwg.org/#requestinit) from the Fetch spec.
 *
 * @experimental
 */
export interface RequestOptionsArgs {
    url?: string | null;
    method?: string | RequestMethod | null;
    /** @deprecated from 4.0.0. Use params instead. */
    search?: string | URLSearchParams | {
        [key: string]: any | any[];
    } | null;
    params?: string | URLSearchParams | {
        [key: string]: any | any[];
    } | null;
    headers?: Headers | null;
    body?: any;
    withCredentials?: boolean | null;
    responseType?: ResponseContentType | null;
}
</code></pre>
