public Nullable<ResultPath> MaterializePath( 
   long pathIndex
)

{
  //using ArcGIS.Core.Data.Knowledge.Extensions;

  await QueuedTask.Run(async () =>
  {
    var ffp_config = new CIMFilteredFindPathsConfiguration();
    ffp_config.Name = "List out FFP Results by Path Length, Min Cost, Max Cost";
    //set up config
    //...

    var results = kg.RunFilteredFindPaths(ffp_config);

    if (results.CountPaths == 0)
    {
      System.Diagnostics.Debug.WriteLine("FFP returned no paths");
      return;
    }

    //print out paths by increasing length, min cost, max cost
    var path_by_len_indices = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingPathLength
                                .Select(idx => idx.index);
    var path_by_min_cost = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingMinPathCost
                                .Select(idx => idx.index);
    var path_by_max_cost = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingMaxPathCost
                                .Select(idx => idx.index);

    var x = 0;
    StringBuilder sb = new StringBuilder();

    foreach (var path_indeces in new List<IEnumerable<long>> {
    path_by_len_indices,
    path_by_min_cost,
    path_by_max_cost})
    {
      if (x == 0)
        sb.AppendLine($"Paths by length: {path_by_len_indices.Count()}");
      else if (x == 1)
        sb.AppendLine($"Paths by min cost: {path_by_min_cost.Count()}");
      else if (x == 2)
        sb.AppendLine($"Paths by max cost: {path_by_max_cost.Count()}");
      x++;
      foreach (var path_idx in path_indeces)
      {
        var path = (ResultPath)results.MaterializePath(path_idx);
        sb.AppendLine(
          $"Path[{path_idx}] length: {path.Length}, min: {path.MinCost} max: {path.MaxCost}");
        var g = 0;
        foreach (var rel_group in path.RelationshipGroups)
        {
          var first_entity = $"({rel_group.FirstEntity.TypeName}:{rel_group.FirstEntity.Uid})";
          var second_entity = $"({rel_group.SecondEntity.TypeName}:{rel_group.SecondEntity.Uid})";

          foreach (var relation in rel_group.Relationships)
          {
            sb.Append($"  [{g++}] ");
            var arrow = relation.SameDirectionAsPath ? "->" : "<-";
            var rel_uid = FormatUID(relation.Relationship.Uid.ToString());
            sb.Append($"{first_entity} '\r\n\t{relation.Relationship.TypeName}:{rel_uid}' {arrow}\r\n" +
              $"\t\t{second_entity}");
            sb.Append($" cost: {relation.Relationship.Cost}\r\n");
          }
        }
      }
    }

  });
}

string FormatUID(string id)
{
  id = id.ToUpperInvariant();
  if (!id.StartsWith('{'))
    id = '{' + id;
  if (!id.EndsWith('}'))
    id += '}';
  return id;
}

{
  //using ArcGIS.Core.Data.Knowledge.Extensions;

  await QueuedTask.Run(async () =>
  {
    var ffp_config = new CIMFilteredFindPathsConfiguration();
    ffp_config.Name = "List out FFP Results Origin, Destination, Other Entities";
    //set up config
    //...

    var results = kg.RunFilteredFindPaths(ffp_config);

    if (results.CountPaths == 0)
    {
      System.Diagnostics.Debug.WriteLine("FFP returned no paths");
      return;
    }

    //print out paths by increasing length, min cost, max cost
    var path_by_len_indices = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingPathLength
                                .Select(idx => idx.index);
    var path_by_min_cost = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingMinPathCost
                                .Select(idx => idx.index);
    var path_by_max_cost = (IEnumerable<long>)results.PathIndicesOrderedByIncreasingMaxPathCost
                                .Select(idx => idx.index);

    var x = 0;
    StringBuilder sb = new StringBuilder();

    foreach (var path_indeces in new List<IEnumerable<long>> {
    path_by_len_indices,
    path_by_min_cost,
    path_by_max_cost})
    {
      if (x == 0)
        sb.AppendLine($"Entities by length: {path_by_len_indices.Count()}");
      else if (x == 1)
        sb.AppendLine($"Entities by min cost: {path_by_min_cost.Count()}");
      else if (x == 2)
        sb.AppendLine($"Entities by max cost: {path_by_max_cost.Count()}");
      x++;
      foreach (var path_idx in path_indeces)
      {
        var path = (ResultPath)results.MaterializePath(path_idx);
        sb.AppendLine(
          $"Path[{path_idx}] length: {path.Length}, min: {path.MinCost} max: {path.MaxCost}");

        var sorted_set = new SortedSet<ulong>();
        sorted_set.Add((ulong)path_idx);
        var per = results.ExtractPathsEntitiesAndRelationships(sorted_set);

        var origin_dest_uids = new List<string>();
        var sep = "";

        sb.Append(" Origin EntitiesUIDs: ");
        foreach (var idx in per.PathsOriginEntitiesUIDsIndexes)
        {
          //See 'List out FFP Results by Path Length, Min Cost, Max Cost' for
          //FormatID method above
          var uid = FormatID(per.EntitiesUIDs[idx].ToString());
          origin_dest_uids.Add(uid);

          var origin =
            $"{sep}{per.EntityTypeNames[per.EntityTypes[idx]]}:{uid}";
          sep = ", ";
          sb.Append($"{origin}");
        }
        sb.AppendLine("");

        sep = "";
        sb.Append(" Destination EntitiesUIDs: ");
        foreach (var idx in per.PathsDestinationEntitiesUIDsIndexes)
        {
          var uid = FormatID(per.EntitiesUIDs[idx].ToString());
          origin_dest_uids.Add(uid);

          var dest =
            $"{sep}{per.EntityTypeNames[per.EntityTypes[idx]]}:{uid}";
          sep = ", ";
          sb.Append($"{dest}");
        }
        sb.AppendLine("");

        sep = "";
        var idx2 = 0;
        sb.Append(" Other EntitiesUIDs: ");
        bool wereAnyOthers = false;
        foreach (var raw_uid in per.EntitiesUIDs)
        {
          var uid = FormatID(raw_uid.ToString());
          if (!origin_dest_uids.Contains(uid))
          {
            var other =
            $"{sep}{per.EntityTypeNames[per.EntityTypes[idx2]]}:{uid}";
            sep = ", ";
            sb.Append($"{other}");
            wereAnyOthers = true;
          }
          idx2++;
        }
        if (!wereAnyOthers)
          sb.Append(" <<none>>");

        //sb.AppendLine("");

        var entity_str = sb.ToString();
        System.Diagnostics.Debug.WriteLine(entity_str);

        sb.Clear();
        sep = "";
      }
    }

  });
}