new MapItem()
Properties:
| Name | Type | Description | 
|---|---|---|
key | 
            
            String | The identifier that maps to this item within the containing Map. | 
value | 
            
            Object | The contents of the item. | 
dateUpdated | 
            
            Date | Date when the Map Item was last updated, given in UTC ISO 8601 format (e.g., '2018-04-26T15:23:19.732Z') |