# File lib/mongoid/relations/referenced/many_to_many.rb, line 118
        def create!(attributes = nil, type = nil, &block)
          super.tap do |doc|
            base.send(metadata.foreign_key).delete_one(doc.id)
            base.push(metadata.foreign_key, doc.id)
            base.synced[metadata.foreign_key] = false
          end
        end