anchor.diff:  
   -define(PARTITION_ASSIGMENT_STRATEGY_ROUNDROBIN, roundrobin). %% default
   
  --type partition_assignment_strategy() :: brod_partition_assignment_strategy().
  +-type partition_assignment_strategy() :: brod:brod_partition_assignment_strategy().
   
   %% default configs
   -define(SESSION_TIMEOUT_SECONDS, 10).
  
positive.code: %% then fetch the committed offsets of each partition.
  %% @end
  -spec get_topic_assignments(#state{}, kpro_ConsumerGroupMemberAssignment()) ->
          brod_received_assignments().
  get_topic_assignments(#state{}, <<>>) -> [];
  get_topic_assignments(#state{} = State, Assignment) ->
    #kpro_ConsumerGroupMemberAssignment
  
negative.code: %%       meaning if two or more offsets for the same topic-partition exist
  %%       in the list, only the one that is closer the head of the list is kept
  %% @end
  -spec commit_offsets(pid(), [{{brod:topic(), brod:partition()}, brod:offset()}]) ->
          ok | {error, any()}.
  commit_offsets(CoordinatorPid, Offsets0) ->
    %% OBS: do not use 'infinity' timeout here.
  