async function findItem(item, propertiesToReturn) {
        const properties = propertiesToReturn !== undefined && propertiesToReturn.length > 0 
            ? propertiesToReturn.map(key => structure[key].name).join(', ')
            : '*'
        const results = await _getTableContext()
            .where(structure[item.key].name, item.value)
            .limit(1)
            .returning(properties)
        return _responseMapper(results[0], propertiesToReturn)
    }
@param {{
  key: string,
  value: any
}} item 
@param {string[]} propertiesToReturn
@returns {Promise<UserItem>}