Multifield::set

public function set(string $commonFieldName, $value): void
{
	$this->load();

	if (!($value instanceof Collection))
	{
		throw new ArgumentTypeException('value', Collection::class);
	}

	if ($this->actual->isEqualTo($value))
	{
		$this->current = null;
	}
	else
	{
		$this->current = clone $value;
	}
}