Step $2$: Determine what is missing

Something is missing from this code in order for it to run. Determine what is missing by evaluating the rest of the code and how it's structured.

Step $3$: Write the missing code

Write the missing code, and indicat

e what class it would be placed in$.$

Step $4$: Evaluate the output

What would the program be$,$ if the missing code was provided and the code was executed?