title: koush AndroidAsync Library Content-Type can't change
body: <p>I want to make post http request using AndroidAsync library but i can't change the content-type to <code>'application/x-www-form-urlencoded'</code> for request</p>
  
  <pre><code>AsyncHttpPost post = new AsyncHttpPost(LOGIN_URL);
  MultipartFormDataBody body = new MultipartFormDataBody();
  body.addStringPart("grant-type", "password");
  body.addStringPart("username", userName);
  body.addStringPart("password", password);
  body.setContentType("application/x-www-form-urlencoded")
  post.setBody(body);
  
  AsyncHttpClient.getDefaultInstance().executeJSONObject(url, new     AsyncHttpClient.JSONObjectCallback() {
  // Callback is invoked with any exceptions/errors, and the result, if available.
  @Override
  public void onCompleted(Exception e, AsyncHttpResponse response, JSONObject result) {
      if (e != null) {
          e.printStackTrace();
          return;
      }
      System.out.println("I got a JSONObject: " + result);
  }
  });
  </code></pre>
  
  <p>I don't know what to do.</p>