Single prooph message class

Message.php

<?php
declare(strict_types = 1);

namespace Acme\Model;

use Prooph\Common\Messaging\DomainMessage;
use Prooph\Common\Messaging\Message as ProophMessage;

class Message extends DomainMessage
{
    /**
     * @var array
     */
    protected $payload;

    public static function command(MessageName $messageName, array $payload = [], array $metadata = []): Message
    {
        return new static($messageName, DomainMessage::TYPE_COMMAND, $payload, $metadata);
    }

    public static function event(MessageName $messageName, array $payload = [], array $metadata = []): Message
    {
        return new static($messageName, DomainMessage::TYPE_EVENT, $payload, $metadata);
    }

    public static function query(MessageName $messageName, array $payload = [], array $metadata = []): Message
    {
        return new static($messageName, DomainMessage::TYPE_QUERY, $payload, $metadata);
    }

    protected function __construct(MessageName $messageName, string $messageType, array $payload, array $metadata)
    {
        $this->messageName = $messageName->getValue();
        $metadata['_message_type'] = $messageType;
        $this->metadata = $metadata;
        $this->setPayload($payload);
        $this->init();
    }

    /**
     * Should be one of Message::TYPE_COMMAND, Message::TYPE_EVENT or Message::TYPE_QUERY
     */
    public function messageType(): string
    {
        return $this->metadata['_message_type'];
    }

    public function payload(): array
    {
        return $this->payload;
    }

    public function withMetadata(array $metadata): ProophMessage
    {
        $messageData = $this->toArray();

        $metadata['_message_type'] = $this->messageType();

        $messageData['metadata'] = $metadata;

        return static::fromArray($messageData);
    }

    protected function setPayload(array $payload): void
    {
        $this->payload = $payload;
    }
}

MessageName.php

<?php

declare(strict_types = 1);

namespace Acme\Model;

use MabeEnum\Enum;

final class MessageName extends Enum
{
    private const COMMAND_NAMESPACE = 'Acme.Command.';
    private const EVENT_NAMESPACE = 'Acme.Event.';
    private const QUERY_NAMESPACE = 'Acme.Query.';

    public const EVENT_TEST = self::EVENT_NAMESPACE . 'Test';
    //...
}

Looks promising