return true if the item is in the list (uses the IsSameAs method).

@param varObj $oItem

@return bool
496098
public function IsInList($oItem)
    {
        $bIsInList = false;
        $iCurPos = $this->getItemPointer();
        $this->GoToStart();
        while (!$bIsInList && ($oTmpItem = &$this->Next())) {
            if ($oTmpItem->id == $oItem->id) {
                $bIsInList = true;
            }
        }
        $this->setItemPointer($iCurPos);

        return $bIsInList;
    }
554989
public function equals(Collection $that) : bool {
        return
            get_class($this) == get_class($that) &&
            $this->items === $that->items;
    }
6930
public function isSatisfiedBy(Item $item): bool
    {
        foreach ($this->specifications as $specification) {
            if (!$specification->isSatisfiedBy($item)) {
                return false;
            }
        }

        return true;
    }
1232563
protected function checkEntry( array $list )
	{
		if( $this->getValue( $list, 'attribute.code' ) === null ) {
			return false;
		}

		if( ( $type = $this->getValue( $list, 'product.lists.type' ) ) && !isset( $this->listTypes[$type] ) )
		{
			$msg = sprintf( 'Invalid type "%1$s" (%2$s)', $type, 'product list' );
			throw new \Aimeos\Controller\Common\Exception( $msg );
		}

		if( ( $type = $this->getValue( $list, 'attribute.type' ) ) && !isset( $this->types[$type] ) )
		{
			$msg = sprintf( 'Invalid type "%1$s" (%2$s)', $type, 'attribute' );
			throw new \Aimeos\Controller\Common\Exception( $msg );
		}

		return true;
	}
1204489
public function hasItem($identifier) {
        return isset($this->itemsPool[$this->prefix . '.' . $identifier]) || isset($this->itemsPool[$identifier]);
    }
974175
public function isSatisfiedBy($item): bool
    {
        if ($this->copyLimit === -1) {
            return true;
        }

        if ($this->copyLimit === 0) {
            return false;
        }

        $query = new LocationQuery([
            'filter' => new Criterion\Subtree($item->pathString),
        ]);

        $searchResults = $this->searchService->findLocations($query);

        if ($this->copyLimit >= $searchResults->totalCount) {
            return true;
        }

        return false;
    }
923379
protected function _setEmosECPageArray($oItem, $sEvent)
    {
        $oItem = $this->_emos_ItemFormat($oItem);

        $this->_ecEvent = [[$sEvent, $oItem->productId, $oItem->productName,
                 $oItem->price, $oItem->productGroup,
                 $oItem->quantity, $oItem->variant1,
                 $oItem->variant2, $oItem->variant3]];
    }
1074228
public function getItem($item)
	{
		return isset($this->items[$item]) ? $this->items[$item] : false;
	}
159131
public function matchItem(ItemInterface $item)
    {
        $request = $this->requestStack->getCurrentRequest();

        $parent = $item->getParent();

        while (null !== $parent->getParent()) {
            $parent = $parent->getParent();
        }

        if ($item->getUri() === $request->getRequestUri() or
            $item->getUri() === $request->attributes->get('__current_folder_path', false)
        ) {
            // URL's completely match
            return true;
        } elseif (
            $item->getUri() !== $request->getBaseUrl().'/' and
            $item->getUri() !== $request->getBaseUrl().'/admin/' and
            $item->getUri() === substr($request->getRequestUri(), 0, strlen($item->getUri())) and
            $request->attributes->get('__selected_inheritance', true) and
            $parent->getExtra('select_intehitance', true)
        ) {
            // URL isn't just "/" and the first part of the URL match
            return true;
        }

        return false;
    }
552172
public function has($itemName)
        {
            return Arrays::exists($itemName, $this->_store) && isset($this->_store[$itemName]['lookupType']);
        }
1137030
public function hasItem(int $position): bool
    {
        return $this->items->exists(
            static function ($key, APIItem $item) use ($position): bool {
                return $item->getPosition() === $position;
            }
        );
    }
634024
public function addItem(Item $oItem)
    {
        if (empty(!$this->iId)) {
            throw new InvoiceException('Invoice has been saved and cannot be modified.');
        }
        $this->aItems[] = $oItem;
        return $this;
    }
1081285
private function isPromotionPlaceholder(LineItem $lineItem): bool
    {
        if ($lineItem->getType() !== self::LINE_ITEM_TYPE) {
            return false;
        }

        return substr($lineItem->getKey(), 0, strlen(PromotionItemBuilder::PLACEHOLDER_PREFIX)) === PromotionItemBuilder::PLACEHOLDER_PREFIX;
    }
197087
public static function isList($val): bool
    {
        if (!\is_array($val) || !isset($val[0])) {
            return false;
        }

        /** @var array $val */
        $keys = \array_keys($val);

        return \array_keys($keys) === $keys;
    }
228966
public function isActive(Item $item)
    {
        // Check if one of the children is active
        foreach ($item->getItems() as $child) {
            if ($this->isActive($child)) {
                return true;
            }
        }

        // Custom set active path
        if ($path = $item->getActiveWhen()) {
            return Request::is(
                $path
            );
        }

        $path = ltrim(str_replace(url('/'), '', $item->getUrl()), '/');

        return Request::is(
            $path,
            $path . '/*'
        );
    }
589315
public function add($item)
    {
        if (is_object($item)) {
            $item = (array) $item;
        }

        $this->validate($item);
        $this->addItem($item);

        return true;
    }
431042
public function hasIn(array $items = [])
    {
        if (\is_null($slug = $this->slug)) {
            return isset($items[$this->value]);
        }

        return isset($items[$slug]);
    }