def METHOD_NAME(self) -> Mapping[str, Any]:
    """
    Returns the request body to set on the refresh request
    Override to define additional parameters
    """
    payload: MutableMapping[str, Any] = {
        "grant_type": self.get_grant_type(),
        "client_id": self.get_client_id(),
        "client_secret": self.get_client_secret(),
        "refresh_token": self.get_refresh_token(),
    }
    if self.get_scopes:
        payload["scopes"] = self.get_scopes()
    if self.get_refresh_request_body():
        for key, val in self.get_refresh_request_body().items():
            # We defer to existing oauth constructs over custom configured fields
            if key not in payload:
                payload[key] = val
    return payload