public function testCompareTo()
{
$dr1 = new DateRange(new DateTime('2006-07-08'), new DateTime('2006-09-05'));
$dr2 = new DateRange(new DateTime('2006-09-06'), new DateTime('2006-09-15'));
$this->assertEquals(-1, $dr1->compareTo($dr2));
$this->assertEquals(1, $dr2->compareTo($dr1));
$dr2 = clone $dr1;
$this->assertEquals(0, $dr1->compareTo($dr2));
}
