public TargetAssignmentBuilder<T> withMembers(
        Map<String, T> members
    ) {
        this.members = members;
        return this;
    }
Adds all the existing members.

@param members   The existing members in the consumer group.
@return This object.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/TargetAssignmentBuilder.java