def update(opts)
      opts = opts.to_hash if Options === opts
      opts.each do |key, value|
        self[key] = value
      end
      self
    end
def update(opts)
      opts = opts.to_hash if Options === opts
      opts.each do |key, value|
        self[key] = value
      end
      self
    end
Updates values from an options hash or options object on this object.
 All keys passed should be key names defined by attributes on the class.

 @example Updating a set of options on an Options object
   opts.update(:template => :guide, :type => :fulldoc)
 @param [Hash, Options] opts
 @return [self]