Faker::Internet.user_name length requirements

Hi.  I'm running into issues where faker rarely generates user names that are less than 4 characters, which is the minimum allowed in my specific case.  So I modified the argument to <tt>Faker::Internet.user_name</tt> can so it can take an <tt>Integer</tt> instance or a <tt>Range</tt> instance.  So in my case I can now call <tt>Faker::Internet.login_name(4..32)</tt> and I'm guaranteed that it generates a user name that is at least 4 characters and at most 32.  I figure I'm not the only one out there with minimum and maximum lengths for logins.  Does this seem like a good idea to you?