How to use the forge-apis.StorageRelationshipsTarget function in forge-apis

function createBodyOfPostStorage(folderId, fileName) {
    // create a new storage for the ouput item version
    let createStorage = new CreateStorage();
    let storageRelationshipsTargetData = new StorageRelationshipsTargetData("folders", folderId);
    let storageRelationshipsTarget = new StorageRelationshipsTarget;
    let createStorageDataRelationships = new CreateStorageDataRelationships();
    let createStorageData = new CreateStorageData();
    let createStorageDataAttributes = new CreateStorageDataAttributes();

    createStorageDataAttributes.name = fileName;
    storageRelationshipsTarget.data = storageRelationshipsTargetData;
    createStorageDataRelationships.target = storageRelationshipsTarget;
    createStorageData.relationships = createStorageDataRelationships;
    createStorageData.type = 'objects';
    createStorageData.attributes = createStorageDataAttributes;
    createStorage.data = createStorageData;
    
    return createStorage;
}