Can you give the example of farewell speech to the teacher who is retired?

An example of a farewell speech to a teacher who is retired would be somewhere along the lines of: Dear Mr/Mrs. Smith, I would like to bid you a great life of retirement. Your years of teaching me as well as others has not gone un noticed. I would like to thank you, on behalf of everyone, I'm sure we will all take something you taught us and apply it later on in life. Then one would close the letter with best regards.