def data=(raw_data)
      new_data = Dis::Model::Data.new(self, raw_data)
      attribute_will_change!('data') unless new_data == dis_data
      @dis_data = new_data
      dis_set :content_hash, if raw_data.nil?
                               nil
                             else
                               Storage.file_digest(new_data.read)
                             end
      dis_set :content_length, dis_data.content_length
    end
def data=(raw_data)
      new_data = Dis::Model::Data.new(self, raw_data)
      attribute_will_change!('data') unless new_data == dis_data
      @dis_data = new_data
      dis_set :content_hash, if raw_data.nil?
                               nil
                             else
                               Storage.file_digest(new_data.read)
                             end
      dis_set :content_length, dis_data.content_length
    end
Assigns new data. This also sets <tt>content_length</tt>, and resets
 <tt>content_hash</tt> to nil.