Ein veränderliches Bankkonto

public function setBalance(Money $balance): void
{
    $this->ensureSameCurrency($balance);
    $this->balance = $balance;
}

<?php declare(strict_types=1);

namespace spriebsch\tfd\softwareArchitecture\eventBased\eventSourcing\mutableAccount;

require __DIR__ . '/autoload.php';

$account = new Account(
    new AccountId('the-id'),
    Currency::EUR,
    new Money(100, Currency::EUR)
);

$account->setBalance(new Money(200, Currency::EUR));

print number_format($account->balance()->amountInCents() / 100, 2) . ' ' . $account->currency()->name . PHP_EOL;