shadows/httpclient/src/main/java/org/robolectric/shadows/httpclient/FakeHttp.java
public static void addPendingHttpResponse(int statusCode, String responseBody, Header... headers) {
    getFakeHttpLayer().addPendingHttpResponse(statusCode, responseBody, headers);
  }
public static void addPendingHttpResponse(int statusCode, String responseBody, Header... headers) {
    getFakeHttpLayer().addPendingHttpResponse(statusCode, responseBody, headers);
  }
Sets up an HTTP response to be returned by calls to Apache's {@code HttpClient} implementers.

@param statusCode   the status code of the response
@param responseBody the body of the response
@param headers      optional headers for the request