client.php

<?php

class Request {
    
}

class Response {
    
    public $body = '';

    public function setBody(string $body): self {
        $this->body = $body;
        return $this;
        
        /*
        $clone = clone $this;
        $clone->body = $body;
        return $clone;
        */
    }

}

class Client {

    public function sendRequest(Request $request): Response {
        $response = new Response();
        return $this->responses[] = $response;
    }
    
    public function execute() {
        foreach($this->responses as $response) {
            $response = $response->setBody((string) random_int(23, 42));
        }
    }

}

$client = new Client();

$request = new Request();
$response1 = $client->sendRequest($request);

$request = new Request();
$response2 = $client->sendRequest($request);

$client->execute();

var_dump($response1, $response2);