Conflict the key name in MongoMapper

I use mongo mapper (0.8.6) in my sinatra service. I have one problem with stack level too deep. The problem is that there is conflict of the key "changes" in my model. Here is my model:

class ChangeLog
  include MongoMapper::Document

  belongs_to :resource

  key :changes, Hash, :required => true
  key :message, String, :required => true
  key :note, String
  key :user_uuid, String, :required => true
  key :user_name, String, :required => true
  timestamps!
end

However, I don't want开发者_运维技巧 to rename my key as in this case, it's the right name for my web service. Any suggestions?

changes is an instance method that will tell you what fields have changed since you last saved the document. Here's an example from MongoMapper's documentation

user = User.create(:name => 'John', :age => 29)

puts user.changed?        # false
puts user.changes.inspect # {}

user.name = 'Steve'
puts user.changed?            # true
puts user.changes.inspect     # {"name"=>["John", "Steve"]}

Unfortunately, you're probably going to need to choose a different name for that field. Maybe "adjustments" or "variations" or "differences" or "modifications"?