public function testGetDobFromAge()
 {
     //10 years
     $dob = Interfacer::getDobFromAge('3652', '2015-03-04');
     $this->assertEquals('2005-03-04', $dob);
     //1 day
     $dob = Interfacer::getDobFromAge('1', '2015-03-04');
     $this->assertEquals('2015-03-03', $dob);
     //100 days
     $dob = Interfacer::getDobFromAge('100', '2015-03-04');
     $this->assertEquals('2014-11-24', $dob);
 }