如何使用OkHTTP测量下载速度？

dependencies {
    implementation 'com.squareup.okhttp3:okhttp:4.9.1'
}

OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
        .url("http://example.com/file.txt")
        .build();

Response response = client.newCall(request).execute();

InputStream inputStream = response.body().byteStream();
long startTime = System.nanoTime();
long downloadedBytes = 0;
byte[] buffer = new byte[4096];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
    // 处理下载的数据
    downloadedBytes += bytesRead;
}

long endTime = System.nanoTime();
long elapsedTime = endTime - startTime;
double downloadSpeed = downloadedBytes / (elapsedTime / 1e9); // 单位是字节/秒

inputStream.close();
response.body().close();