nspl\ds\Set::fromArray PHP Метод

    public static function fromArray(array $array)
    {
        $result = new static();
        foreach ($array as $element) {
            $result->array[static::getElementKey($element)] = $element;
        }
        return $result;
    }

    }
}
echo "Matrix 3x3:\n";
print_r(map(methodCaller('toArray'), $matrix->toArray()));
// casting default array with all nested default arrays to PHP array
// 3. Set example
$set = set(1, 2);
$set->add('hello');
$set[] = 'world';
$set->update([3, 4], ['answer', 42]);
echo "Set:\n";
print_r($set->toArray());
foreach (['hello', 3, 4, 'answer', 42] as $element) {
    $set->delete($element);
}
echo "Set:\n";
print_r($set->toArray());
$array = [1, 2, 3];
$intersection = $set->intersection($array);
echo "Intersection:\n";
print_r($intersection->toArray());
$anotherSet = Set::fromArray([1, 2, 3]);
$difference = $set->difference($anotherSet);
echo "Difference:\n";
print_r($difference->toArray());
$iterator = new \ArrayIterator([1, 2, 3]);
$union = $set->union($iterator);
echo "Union:\n";
print_r($union->toArray());
$isSubset = $set->isSubset([1, 2, 'hello', 'world']);
$isSuperset = $set->isSuperset([1, 2]);