var logs = await web3.eth.getPastLogs({
address : collection.address,
topics : [web3.utils.sha3("NewItem(uint256,address)")]
//If not already done, initialize the items array in the Collection
collection.items = collection.items || [];
//Object Id is the first argument param of the Event
var collectionItemObjectId = web3.eth.abi.decodeParameter("uint256", log.topics[1]);
//Object ERC20 Wrapper is the second param of the Event
var collectionItemInteroperableInterfaceAddress = web3.eth.abi.decodeParameter("uint256", log.topics[2]);
var collectionItemInteroperableInterface = new web3.eth.Contract(configuration.IEthItemInteroperableInterfaceABI, collectionItemInteroperableInterfaceAddress);
//Get my balance of this objectId
var myBalance = await collection.methods.balanceOf(web3.eth.accounts[0], collectionItemObjectId).call();
//Assemble the Collection Item, you can add all the additional info you want (e.g. cross-referencing the Collection this Item belongs to)
objectId : collectionItemObjectId,
address : collectionItemInteroperableInterfaceAddress,
contract : collectionItemInteroperableInterface,
//Add every single Collection Item to the corresponding Collection's array
collection.items.push(collectionItem);