Direct Message Membership Activity

Direct message membership activity.

Property Name	Type	Description	Filter Group and Version	Available Version
`activityDate`	Date	Direct message member activity date.	Small, 40.0	40.0
`actor`	User Summary	User who changed the direct message membership.	Small, 40.0	40.0
`membersAdded`	Direct Message Member Collection	Members added to the direct message as part of the activity.	Small, 40.0	40.0
`membersRemoved`	Direct Message Member Collection	Members removed from the direct message as part of the activity.	Small, 40.0	40.0

Chatter REST API Developer Guide