protected override object Fallback(CommandFailedException instigator)
 {
     Thread.Sleep(_sleepDuration);
     return new { };
 }
 protected override object Fallback(CommandFailedException instigator)
 {
     return new { };
 }
 protected override object Fallback(CommandFailedException instigator)
 {
     throw instigator;
 }
 protected override object Fallback(CommandFailedException instigator)
 {
     FallbackCalled = true;
     return Value;
 }