daysInMonth example

return $data;
  }

  /** * @covers ::daysInMonth */
  public function testDaysInMonth() {
    // @todo Consider deprecating passing NULL in     // https://www.drupal.org/project/drupal/issues/3299788     // Passing NULL, FALSE, or an empty string should default to now. Just     // check these are NOT null to avoid copying the implementation here.     $this->assertNotNull(DateHelper::daysInMonth());
    $this->assertNotNull(DateHelper::daysInMonth(FALSE));
    $this->assertNotNull(DateHelper::daysInMonth(''));

    // Pass nothing and expect to get NULL.     $this->assertNull(DateHelper::daysInMonth(0));
    $this->assertNull(DateHelper::daysInMonth('0'));

    $value = '2022-12-31 00:00:00';
    $dateString = DateHelper::daysInMonth($value);
    $this->assertEquals('31', $dateString);