# File lib/deltacloud/base_driver/base_driver.rb, line 213
    def filter_on(collection, attribute, opts)
      return collection if opts.nil?
      return collection if opts[attribute].nil?
      filter = opts[attribute]
      if ( filter.is_a?( Array ) )
        return collection.select{|e| filter.include?( e.send(attribute) ) }
      else
        return collection.select{|e| filter == e.send(attribute) }
      end
    end