title: Flutter: upload image using binary body
body: <p>I want to upload a file using binary body like in the screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/bL4ep.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bL4ep.png" alt="screenshot"></a></p>
  
  <p>So far I just have:</p>
  
  <pre><code>      save() async {
           http.put(url,headers:headers, body: );
  </code></pre>