Event argument forwarded by a GroupChatEndpoint when a chat room invitation is received.
Assembly: Microsoft.Rtc.Collaboration.GroupChat(in Microsoft.Rtc.Collaboration.GroupChat.dll)
Chat room invitations are issued by the group chat server when a user is granted membership to a chat room. The issuing of chat room invitations is conditional on the chat room properties. Invitations are used to raise awareness of the existence of a chat room, and encourage new members to join.