Add a clearer example for with_options (lifted from the Active Support guide).

activesupport/lib/active_support/core_ext/object/with_options.rb

@@ -7,13 +7,27 @@ class Object
   # provided. Each method called on the block variable must take an options
   # hash as its final argument.
   #
-  #   with_options :order => 'created_at', :class_name => 'Comment' do |post|
-  #     post.has_many :comments, :conditions => ['approved = ?', true], :dependent => :delete_all
-  #     post.has_many :unapproved_comments, :conditions => ['approved = ?', false]
-  #     post.has_many :all_comments
+  # Without with_options, this code contains duplication:
+  #
+  #   class Account < ActiveRecord::Base
+  #     has_many :customers, :dependent => :destroy
+  #     has_many :products,  :dependent => :destroy
+  #     has_many :invoices,  :dependent => :destroy
+  #     has_many :expenses,  :dependent => :destroy
   #   end
   #
-  # Can also be used with an explicit receiver:
+  # Using with_options, we can remove the duplication:
+  #
+  #   class Account < ActiveRecord::Base
+  #     with_options :dependent => :destroy do |assoc|
+  #       assoc.has_many :customers
+  #       assoc.has_many :products
+  #       assoc.has_many :invoices
+  #       assoc.has_many :expenses
+  #     end
+  #   end
+  #
+  # It also be used with an explicit receiver:
   #
   #   map.with_options :controller => "people" do |people|
   #     people.connect "/people",     :action => "index"