PHPUnit_Framework_Assert::isNull PHP Method

    public static function isNull()
    {
        return new PHPUnit_Framework_Constraint_IsNull();
    }

/**
 * Returns a PHPUnit_Framework_Constraint_IsNull matcher object.
 *
 * @return PHPUnit_Framework_Constraint_IsNull
 * @since  Method available since Release 3.3.0
 */
function isNull()
{
    return PHPUnit_Framework_Assert::isNull();
}