public void Print() { foreach (var frame in TextFrames) { TextFrame value1 = null; ListTextFrame value2; if (frame is TextFrame) { value1 = frame as TextFrame; } else if (frame is ListTextFrame) { value2 = frame as ListTextFrame; } else { throw new NotImplementedException(); } if (_output != null) { _output.WriteLine($"{value1?.ToString()}: {value1?.Value}", Severity.Info); } } }