code: def _get_content_type(self, file):
          
          if file.mimetype:
              return file.mimetype
  
          # get file extension
          _, extension = os.path.splitext(file.name)
          extension = extension.strip('.')
  
          # Make an educated guess about what the Content-Type should be.
          return media_types[extension] if extension in media_types else 'binary/octet-stream'
docs: Return content type of file. If file does not
          have a content type, make a guess.