public void Planarize( 
   Layer layer,
   long oid,
   Nullable<double> clusterTolerance
)

// Planarizes the specified feature in the given feature layer.
await QueuedTask.Run(() =>
  {
    // note - EditOperation.Planarize requires a standard license. 
    //  An exception will be thrown if Pro is running under a basic license. 

    var planarizeFeatures = new EditOperation() { Name = "Planarize Features" };

    // Planarize one or more features
    planarizeFeatures.Planarize(featureLayer, [objectId]);

    // Execute to execute the operation
    // Must be called within QueuedTask.Run
    if (!planarizeFeatures.IsEmpty)
    {
      //Execute and ExecuteAsync will return true if the operation was successful and false if not
      var result = planarizeFeatures.Execute();
      //or use async flavor
      //await planarizeFeatures.ExecuteAsync();
    }
  });

// Performs a sequence of editing operations on a feature, including clipping, cutting, and planarizing.
await QueuedTask.Run(() =>
  {
    //Multiple operations can be performed by a single
    //edit operation.
    var clipCutPlanarizeFeatures = new EditOperation() { Name = "Clip, Cut, and Planarize Features" };
    clipCutPlanarizeFeatures.Clip(featureLayer, objectId, clipPolygon);
    clipCutPlanarizeFeatures.Split(featureLayer, objectId, cutLine);
    clipCutPlanarizeFeatures.Planarize(featureLayer, objectId);

    if (!clipCutPlanarizeFeatures.IsEmpty)
    {
      //Note: An edit operation is a single transaction. 
      //Execute the operations (in the order they were declared)
      //Execute and ExecuteAsync will return true if the operation was successful and false if not
      clipCutPlanarizeFeatures.Execute();
      //or use async flavor
      //await clipCutPlanarizeFeatures.ExecuteAsync();
    }
  });