/**
  * Tests the JDatabaseQuery::DateAdd method
  *
  * @param   datetime  $date      The date or datetime to add to.
  * @param   string    $interval  The maximum length of the text.
  * @param   string    $datePart  The part of the date to be added to (such as day or micosecond)
  * @param   string    $expected  The expected result.
  *
  * @return  void
  *
  * @dataProvider  seedDateAdd
  * @since   13.1
  */
 public function testDateAdd($date, $interval, $datePart, $expected)
 {
     $this->assertThat($this->_instance->dateAdd($date, $interval, $datePart), $this->equalTo($expected));
 }