code: def _send_headers(self, status_code=200, content_type='application/json', more_headers={}):
          
          self.send_response(status_code)
          self.send_header('content-type', content_type)
          self.send_header('Access-Control-Allow-Origin', '*')    # CORS
          for (hdr, val) in more_headers.items():
              self.send_header(hdr, val)
  
          self.end_headers()
docs: Generate and reply headers