1. Set Equality across HashSet and TreeSet. Write a program that creates a HashSet of strings and a TreeSet of the same strings (i.e., strings with the same content, say "apple" and "pear"), and show that you can use set equals to test their equality. Read page 102 on Equality in general. Note that the code for Date equality, page 103, requires the two objects to be of the same class, but this is not required in general (but obviously it's not disallowed either).