[Serializable]
    class Class1
    {
         ....
        
        // для сохранения состояния
        private byte[] originalState;

        // ссылка на себя
        private Class1 selfClass1; 

        public virtual void BeginEdit()
        {
            BinaryFormatter formatter = new BinaryFormatter();

            this.selfClass1 = this;

            using (MemoryStream stream = new MemoryStream())
            {
                formatter.Serialize(stream, this.selfClass1);
                stream.Position = 0;
                originalState = new byte[stream.Length];
                stream.Read(originalState, 0, (int)stream.Length);
            }
        }

        public virtual void CancelEdit()
        {
            if (originalState != null)
            {
                BinaryFormatter formatter = new BinaryFormatter();

                this.selfClass1 = this;

                using (MemoryStream stream = new MemoryStream())
                {
                    stream.Write(originalState, 0, originalState.Length);
                    stream.Position = 0;
                    this.selfClass1 = (Class1)formatter.Deserialize(stream);

                    originalState = null;
                }

            }
        }
    }

            
        public virtual Class1 ReturnOriginalClass()
        {
            this.selfClass1 = null;

            if (originalState != null)
            {
                BinaryFormatter formatter = new BinaryFormatter();

                using (MemoryStream stream = new MemoryStream())
                {
                    stream.Write(originalState, 0, originalState.Length);
                    stream.Position = 0;
                    this.selfClass1 = (Class1)formatter.Deserialize(stream);

                    originalState = null;
                }                
            }

            return this.selfClass1;
        }