TypeError: is not a function typescript class
<p>I'm getting the following error in my typescript class and cannot understand why. All I am doing is trying to call a helper function passing the token. </p>

<p>Error:</p>

<blockquote>
  <p>post error:  TypeError: this.storeToken is not a function(…)</p>
</blockquote>

<p>Class: </p>

<pre class="lang-js prettyprint-override"><code>/**
 * Authentication Service:
 *
 * Contains the http request logic to authenticate the
 * user.
 */
import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions } from '@angular/http';

import 'rxjs/Rx';
import { Observable } from 'rxjs/Observable';

import { AuthToken } from './auth-token.service';

import { User } from '../../shared/models/user.model';

@Injectable()
export class Authenticate {

  constructor(
    private http: Http,
    private authToken: AuthToken
  ) {}

  post(user: User): Observable&lt;any&gt; {
    let url = 'http://localhost:4000/';
    let body = JSON.stringify(user);
    let headers = new Headers({ 'content-type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(url + 'login', body, options)
      .map(this.handleData)
      .catch(this.handleError);
  }

  private storeToken(token: string) {
    this.authToken.setToken(token);
  }

  private handleData(res: Response) {
    let body = res.json();
    this.storeToken(body.token);
    return body.fields || {};
  }

  private handleError(error: any) {
    console.error('post error: ', error);
    return Observable.throw(error.statusText);
  }
}
</code></pre>

<p>I am new to typescript so I'm sure I am missing something ridiculously simple. Any assist would be great.</p>

<p>Thanks.</p>