Write a main function. In the main function, write some code that will test the 5 functions above (remove_punc, word_count, remove_non_alpha, add_unique, and letter_frequency). The purpose of this main function is to ensure that all of the functions are working correctly, before we try to use these functions in another program. Write the if statement to check for standalone program. It's up to you to decide how much testing to do. For grading purposes, you must call each function at least once and print the results with clear, meaningful text. 7. Write the if statement to check for standalone program. (Note: Memorize this. It will be on the final exam.) if __name__