I am now writing the last method which is called a Precondition method

I am now writing the last method called a Precondition method. This is the last page of code of a seven page Java program. There is also a seeds class file that is about half a page and a main method file that is also about half a page. The seeds file I rewrote from one of the professor's files last week. Yesterday night, I wrote the main method and the professor looked at it today and said, it looked fine. I started with a file of the professor's as he suggested for the longer file and started to rewrite it last weekend and now have about one page of this longer seven page file to write. The last page has what is called a Precondition method and I will now work on that tonight.