# File lib/mongo_mapper/plugins/identity_map.rb, line 123
    def find_one(opts={})
      query = clone.amend(opts)

      if identity_map && query.simple? && (document = identity_map.get_from_identity_map(query[:_id]))
        document
      else
        super.tap do |doc|
          doc.remove_from_identity_map if doc && query.fields?
        end
      end
    end