def attribute(name, options = {})
      attributes << name unless attributes.include?(name)
      defaults[name] = options[:default] if options.has_key?(:default)

      if options.has_key?(:accessors)
        to_define = Array(options[:accessors]) & accessor_options
      else # Default methods
        to_define = [:reader, :writer]
      end

      to_define.each{|m| send("#{m}_for", name) }
    end
def attribute(name, options = {})
      attributes << name unless attributes.include?(name)
      defaults[name] = options[:default] if options.has_key?(:default)

      if options.has_key?(:accessors)
        to_define = Array(options[:accessors]) & accessor_options
      else # Default methods
        to_define = [:reader, :writer]
      end

      to_define.each{|m| send("#{m}_for", name) }
    end
Declares persisted attributes.
 All attributes are stored on the Riak hash.

 Example:
   class User
     include Ork::Document

     attribute :name
   end

   # It's the same as:

   class User
     include Ork::Document

     def name
       @attributes[:name]
     end

     def name=(name)
       @attributes[:name] = name
     end
   end