@protocol FIRInviteDelegate <NSObject>
The protocol to receive the result of the invite action.
Reports the status of the invite action. |invitationsIds| holds the IDs of the invitations sent by the user. |error| is nil upon success. Otherwise, it will contain one of the errors defined in FIRInvitesError.h.
- (void)inviteFinishedWithInvitations: (nonnull NSArray<NSString *> *)invitationIds error:(nullable NSError *)error;