/// ensure there is at least one server.
ensure there is at least one server.
ensure there is at least one server .
fn valid_servers_or_error(&self) -> Result<(), ClientError> {
        if self.sc_addr.is_some() || self.spu_addr.is_some() || self.kf_addr.is_some() {
            Ok(())
        } else {
            Err(ClientError::IoError(IoError::new(
                ErrorKind::Other,
                "no sc address or spu address is provided",
            )))
        }
    }
fn valid_servers_or_error ( & self ) -> Result < ( ) , ClientError > { if self . sc_addr . is_some ( ) || self . spu_addr . is_some ( ) || self . kf_addr . is_some ( ) { Ok ( ( ) ) } else { Err ( ClientError :: IoError ( IoError :: new ( ErrorKind :: Other , " " , ) ) ) } }
ensure there is at least one server.
ensure there is at least one server .
&self