anchor.diff:                                        timeout=Timeout,
                                         vnode_master=VNodeMaster,
                                         plan_fun = PlanFun,
  -                                      coverage_plan_mod = PlanMod}) ->
  -    CoveragePlan = find_plan(PlanMod,
  +                                      coverage_plan_fn = CoveragePlanFn}) ->
  +    CoveragePlan = find_plan(CoveragePlanFn,
                                VNodeSelector,
                                NVal,
                                PVC,
  
positive.code:       From={_, ReqId, _},
        RequestArgs]) ->
      {Request, VNodeSelector, NVal, PrimaryVNodeCoverage,
       NodeCheckService, VNodeMaster, Timeout, PlannerMod, ModState} =
          Mod:init(From, RequestArgs),
      maybe_start_timeout_timer(Timeout),
      PlanFun = plan_callback(Mod),
  
negative.code:     ok.
  
  %% @private
  find_plan(_CoveragePlanFn, #vnode_coverage{}=Plan, _NVal, _PVC, _ReqId, _Service,
            _Request) ->
      interpret_plan(Plan);
  find_plan(CoveragePlanFn, Target, NVal, PVC, ReqId, Service, Request) ->
      CoveragePlanFn(Target, NVal, PVC, ReqId, Service, Request).
  
  %% @private
  %% Take a `vnode_coverage' record and interpret it as a mini coverage plan
  