title: Convert python requests to http flutter
body: <p>I have a python code like:</p>
  <pre class="lang-py prettyprint-override"><code>files = {
      'image_url': (None, ''),
      'image_content': (None, ''),
      'filename': (None, ''),
      'h1': (None, 'en'),
      'bih': (None, '179'),
      'biw': (None, '1600'),
      'encoded_image': (None, open(file,'rb')),
  }
  response = requests.post('https://www.google.co.in/searchbyimage/upload', files=files, allow_redirects=True)
  </code></pre>
  <p>The curl command is<br />
  <code>curl -F encoded_image=@/path/to/image.jpg https://www.google.de/searchbyimage/upload </code></p>
  <p>How can I convert this code to flutter HTTP or any other package (like dio)?</p>