Start with a fresh copy of the C++ calculator code. See exercise 5 for directions on downloading and

Start with a fresh copy of the C++ calculator code. See exercise 5 for directions on downloading and unzipping the files. Compile it with the make clean and make commands. Run the program to verify that it does correctly add two integers together. Then change the token.h file and remove virtual keyword from the getLex method of theToken class but leave the LexicalToken . Run the program again and it will likely not add two integers together correctly. Explain why this happens. What happened to the C++ code that removing the keyword