Signature of the callback used to add a member to the group. This should perform the necessary operations in the underlying IM protocol to cause the member to be added.
An object implementing the group interface with this mixin
The handle of the contact to be added
A message to be sent if the protocol supports it
Signature of the callback used to add a member to the group. This should perform the necessary operations in the underlying IM protocol to cause the member to be added.