MathPHP\SetTheory\SetTest::testFluentInterface PHP Метод

    public function testFluentInterface()
    {
        $A = new Set();
        $A->add(1)->add(2)->add(3)->remove(2)->add(4)->remove(1)->addMulti([5, 6, 7])->add(new Set([1, 2, 3]))->removeMulti([5, 6]);
        $B = new Set([3, 4, 7, new Set([1, 2, 3])]);
        $this->assertEquals($B, $A);
    }