<?php

namespace TomPHP\ConfigServiceProvider\Exception;

use DomainException;

final class EntryDoesNotExistException extends DomainException implements Exception
{
    use ExceptionFactory;

    /**
     * @param string key
     *
     * @return self
     */
    public static function fromKey($key)
    {
        return self::create('No entry found for "%s".', $key);
    }
}

<?php

namespace TomPHP\ConfigServiceProvider\Exception;

use DomainException;

final class EntryDoesNotExistException extends DomainException implements Exception
{
    use ExceptionFactory;

    /**
     * @param string $key
     *
     * @return self
     */
    public static function fromKey($key)
    {
        return self::create('No entry found for "%s".', $key);
    }
}

Add missing $ to docblock
Fix: Add missing $ to docblock
