`alias_method_chain': undefined method `find' for class `Act

Rails
1

I can’t seem to be able to override the :find method in the model base
class, for example, in /lib/usermonitor.rb:

module ActiveRecord
module UserMonitor
def self.included(base)
base.class_eval do
alias_method_chain :find, :user

    def current_site
      Thread.current[:user]
    end
  end
end
def find_with_user(*args)
  ...
end

end
end

I got this error:

alias_method_chain': undefined methodfind’ for class
`ActiveRecord::Base’ (NameError)

However, overriding :create and :update methods work fine. Why?