src/CLI/InitCommand.php
private static function checkExchangesConfiguration(array $configuration)
    {
        Assertion::keyIsset($configuration, 'exchanges', 'You must provide an `exchanges` configuration');

        $exchanges = $configuration['exchanges'];
        Assertion::isArray($exchanges, 'The `exchanges` configuration must be an array');

        /** @var string[][] $exchanges */
        foreach ($exchanges as $exchangeInformation) {
            self::checkExchangeConfiguration($exchangeInformation);
        }
    }
private static function checkExchangesConfiguration(array $configuration)
    {
        Assertion::keyIsset($configuration, 'exchanges', 'You must provide an `exchanges` configuration');

        $exchanges = $configuration['exchanges'];
        Assertion::isArray($exchanges, 'The `exchanges` configuration must be an array');

        /** @var string[][] $exchanges */
        foreach ($exchanges as $exchangeInformation) {
            self::checkExchangeConfiguration($exchangeInformation);
        }
    }
@param array $configuration

@throws AssertionFailedException