Наследование от IO.Filestream - C#

public class Element : FileStream
        {
            public string Key { get; set; }
            public string FileNameFrom { get; set; }
            public string FileNameTo { get; set; }
            public void FromStringToBase64()
            {
               //SomeCode
            }
            public void FromBase64ToString()
            {  
                SomeCode//    
            }
            public void GammaCode()
            {
                //SomeCode
            }
            public void GammaDecode()
            {
               //SomeCode
            }            
            public void Activity()
            {
                this.FromStringToBase64();
            }
        }