/**
* @test
*/
function genGou()
{
$h = new DateTime('1989-01-08');
$this->assertEquals('1989-01-08 00:00:00', (string) $h);
$this->assertEquals('平成', $h->format('%G'));
$this->assertEquals('昭和', $h->modify('-1 day')->format('%G'));
$this->assertEquals('平成 元年 日 日曜日', $h->format('%G %Y年 %w %W'));
$this->assertEquals('平成 2年', $h->modify('1 year')->format('%G %Y年'));
$this->assertEquals('平成', $h->jaGenGou());
$this->assertEquals('昭和', $h->modify('-1 day')->jaGenGou());
$h = new DateTime('1868-01-25');
$this->assertEquals('明治', $h->format('%G'));
$this->assertEquals(1868, $h->modify('-1 day')->format('%Y'));
$this->assertEquals('', $h->modify('-1 day')->format('%G'));
}
