private WebResourceResponse shouldIntercept(String url) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                    return null;
                }

                if (url.matches(".*frameworks.*.js")) {
                    InputStream in1 = null;
                    InputStream in2 = null;
                    Response response = null;
                    try {
                        response = new OkHttpClient.Builder()
                                .build()
                                .newCall(new Request.Builder().get().url(url).build())
                                .execute();

                        if (response.body() != null) {
                            in1 = response
                                    .body()
                                    .byteStream();
                        }

                        in2 = getAssets().open("polyfills.js");
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                    if (response == null) {
                        return null;
                    }

                    SequenceInputStream inputStream = new SequenceInputStream(in2, in1);
                    return new WebResourceResponse("text/javascript", "utf-8", inputStream);
                } else {
                    return null;
                }
            }
This method will inject polyfills to the auth javascript if the version is
below Lollipop. After Lollipop WebView is updated via the Play Store so the polyfills
are not needed.

@param url The requests url
@return null if there request should not be altered or a new response
    instance with polyfills.
app/src/main/java/com/github/pockethub/android/accounts/LoginWebViewActivity.java