feat(services): add generator for public holidays in cz

tests/Unit/Services/WorkingDays/PublicHolidaysGeneratorFactoryTest.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\Services\WorkingDays;
+
+use App\Services\WorkingDays\PublicHolidays\Generator\PublicHolidaysCzechGenerator;
+use App\Services\WorkingDays\PublicHolidays\PublicHolidaysGeneratorFactory;
+use Tests\TestCase;
+
+class PublicHolidaysGeneratorFactoryTest extends TestCase
+{
+    public function testPublicHolidaysGeneratorFactoryWillReturnCzechGeneratorForCZ(): void
+    {
+        $factory = new PublicHolidaysGeneratorFactory();
+        $this->assertInstanceOf(PublicHolidaysCzechGenerator::class, $factory->createPublicHolidaysGeneratorForCountry('CZ'));
+    }
+
+    public function testRuntimeExceptionGeneratedForUnknownState(): void
+    {
+        $factory = new PublicHolidaysGeneratorFactory();
+        $this->expectException(\RuntimeException::class);
+        $factory->createPublicHolidaysGeneratorForCountry('XZ');
+    }
+}