private void ensureGroupMembersIsMutable() {
        com.google.protobuf.Internal.ProtobufList<im.turms.client.model.proto.model.group.GroupMember> tmp =
                groupMembers_;
        if (!tmp.isModifiable()) {
            groupMembers_ = com.google.protobuf.GeneratedMessageLite.mutableCopy(tmp);
        }
    }
<code>repeated .im.turms.proto.GroupMember group_members = 1;</code>
turms-client-kotlin/src/main/java/im/turms/client/model/proto/model/group/GroupMembersWithVersion.java