public function testV7MicrosecondPrecision()
{
    $testCases = [
        '1645557742.000001',
        '1645557742.123456', 
        '1645557742.999999'
    ];
    
    foreach ($testCases as $timeStr) {
        $timestamp = \DateTimeImmutable::createFromFormat('U.u', $timeStr);
        $uuidStr = UuidV7::generate($timestamp);
        $uuid = UuidV7::fromString($uuidStr);
        
        $expected = $timestamp->format('U.u');
        $actual = $uuid->getDateTime()->format('U.u');
        
        $this->assertSame($expected, $actual);
    }
}