public sealed class Inspector : ArcGIS.Desktop.Framework.Contracts.PropertyChangedBase, System.Collections.Generic.IEnumerable<Attribute>, System.Collections.IEnumerable, System.ComponentModel.INotifyPropertyChanged  

// Adds a custom validation rule to the "Mineral" field of the specified feature layer.
await QueuedTask.Run(() =>
{
  var insp = new Inspector();
  insp.LoadSchema(featureLayer);
  var attrib = insp.Where(a => a.FieldName == "Mineral").First();
  attrib.AddValidate(() =>
  {
    if (attrib.CurrentValue.ToString() == "Salt")
      return [];
    else return [ArcGIS.Desktop.Editing.Attributes.Attribute.ValidationError.Create("Error", Severity.Low)];
  });
});

await QueuedTask.Run(() =>
{
  // get selected feature into inspector
  var selectedFeatures = activeMap.GetSelection();
  var insp = new Inspector();
  insp.Load(selectedFeatures.ToDictionary().Keys.First(), selectedFeatures.ToDictionary().Values.First());
  // read a blob field and save to a file
  var msw = new MemoryStream();
  msw = insp["BlobField"] as MemoryStream;
  using (FileStream file = new(@"d:\temp\blob.jpg", FileMode.Create, FileAccess.Write))
  {
    msw.WriteTo(file);
  }
  // read file into memory stream
  var msr = new MemoryStream();
  using (FileStream file = new(@"d:\images\Hydrant.jpg", FileMode.Open, FileAccess.Read))
  {
    file.CopyTo(msr);
  }
  //put the memory stream in the blob field and save to feature
  var op = new EditOperation() { Name = "Blob Inspector" };
  insp["Blobfield"] = msr;
  op.Modify(insp);
  if (!op.IsEmpty)
  {
    var result = op.Execute(); //Execute and ExecuteAsync will return true if the operation was successful and false if not
  }
});