def interpret(line)
      args = line.split(' ')
      command = args.shift
      action = config.lookup(command)

      if action.nil?
        config.output.puts %Q(Unrecognized command: #{command}. Type "help" for a list of valid commands)
      else
        action.perform(args: args)
      end
    end
def interpret(line)
      args = line.split(' ')
      command = args.shift
      action = config.lookup(command)

      if action.nil?
        config.output.puts %Q(Unrecognized command: #{command}. Type "help" for a list of valid commands)
      else
        action.perform(args: args)
      end
    end
@param config [Config] the application configuration
 Performs the action (if valid) for the given input command line

 @param line [String] the entire command line string.