docs: def handle(self, request_headers={}, signature_header=None):
          """Handle request."""
          if self.client.webhook_secret is None:
              raise ValueError('Error: no webhook secret.')
          encoded_header = self._get_signature_header(signature_header, request_headers)
          decoded_request = self._decode_request(encoded_header)
          if 'type' not in decoded_request:
              raise ValueError("Error invalid request: no type field found.")
          handler = self._getHandlerForEvent(decoded_request['type'])
          if handler is None:
              return
          if (self._get_fct_number_of_arg(handler) == 1):
              handler(decoded_request)
              return
          handler(decoded_request, decoded_request['type'])