 Alright, so in this application, I have once again initialized an instance of this log API class. Now one thing to notice here is that we have removed all the if preprocessor directive from this code. Now let's open this class. Now to conditionally execute this method based on the compilation symbol, we need to add conditional attribute. But before that, to support that conditional attribute, I need to add one namespace which is system.diagnostics. And then I need to define the conditional attribute. And then in the parameter, I need to specify the symbol name which is sandbox. And now when we execute this application, we are able to log all the messages in this console. And now let me remove that compilation symbol from this application. So for that, let me open the property window of this application. Go to the build section and let me remove this symbol. And now when I run this application again, the messages are not displayed in the console. So this conditional attribute tells to the compiler that whenever this method is called and if the sandbox symbol is defined, then include the call to this method. And if the symbol is not defined, then call to the method will be removed from the compiled assembly.