tapichu/saas-class — pull request #2 by lporras (2012-03-04 04:55:01+00:00)
Title: palindrome? methods should accepts nil

on the examples given for palindrome? method says "that nil is also ok":

palindrome?("A man, a plan, a canal -- Panama") #=> true
palindrome?("Madam, I'm Adam!") # => true
palindrome?("Abracadabra") # => false (nil is also ok)

so I think you should include the nil into palindromes array