/**
  * @dataProvider datesAndOffsets
  */
 public function testDateFromOffset($start, $offset, $expected)
 {
     $billingAgreement = new BillingAgreement();
     $newDate = $billingAgreement->dateFromOffset($start, $offset);
     $this->assertEquals($expected, $newDate);
     $this->assertNotSame($newDate, $start);
 }