def by_planner_plan_id(self,planner_plan_id: str) -> PlannerPlanItemRequestBuilder:
        """
        Provides operations to manage the plans property of the microsoft.graph.planner entity.
        param planner_plan_id: The unique identifier of plannerPlan
        Returns: PlannerPlanItemRequestBuilder
        """
        if planner_plan_id is None:
            raise TypeError("planner_plan_id cannot be null.")
        from .item.planner_plan_item_request_builder import PlannerPlanItemRequestBuilder

        url_tpl_params = get_path_parameters(self.path_parameters)
        url_tpl_params["plannerPlan%2Did"] = planner_plan_id
        return PlannerPlanItemRequestBuilder(self.request_adapter, url_tpl_params)

        Provides operations to manage the plans property of the microsoft.graph.planner entity.
        param planner_plan_id: The unique identifier of plannerPlan
        Returns: PlannerPlanItemRequestBuilder
        
msgraph/generated/planner/plans/plans_request_builder.py