code: def add_member(self, urls):
          
          member_add_request = etcdrpc.MemberAddRequest(peerURLs=urls)
  
          member_add_response = self.clusterstub.MemberAdd(
              member_add_request,
              self.timeout,
              credentials=self.call_credentials,
              metadata=self.metadata
          )
  
          member = member_add_response.member
          return etcd3.members.Member(member.ID,
                                      member.name,
                                      member.peerURLs,
                                      member.clientURLs,
                                      etcd_client=self)
docs: Add a member into the cluster.
  
          :returns: new member
          :rtype: :class:`.Member`