docs: def get_content_type(content_type):
      """Extract the MIME type value from a content type string.
  
      Removes any subtype and parameter values that may be present in the string.
  
      Args:
        content_type: str
          String with content type and optional subtype and parameter fields.
  
      Returns:
        str: String with only content type
  
      Example:
  
      ::
  
        Input:   multipart/form-data; boundary=aBoundaryString
        Returns: multipart/form-data
  
      """
      m = email.message.Message()
      m['Content-Type'] = content_type
      return m.get_content_type()