    # File lib/termtter/command.rb, line 60
        def call(cmd = nil, arg = nil, original_text = nil)
          from = Time.now
          arg = case arg
            when nil
              ''
            when String
              arg
            else
              raise ArgumentError, 'arg should be String or nil'
            end
          Termtter::Client.logger.debug { "command: #{cmd} #{arg}" }
          result = exec_proc.call(arg)
          Termtter::Client.logger.debug { "command: #{cmd} #{arg} #{'%.2fsec' % (Time.now - from)}" }
          result
        rescue => e
          Termtter::Client.logger.debug { "command: #{cmd} #{arg} #{e.message} #{'%.2fsec' % (Time.now - from)}" }
          raise e
        end