code: def cli(self, commands):
          
          cli_output = dict()
          if type(commands) is not list:
              raise TypeError('Please enter a valid list of commands!')
  
          for command in commands:
              output = self._send_command(command)
              if 'Invalid input detected' in output:
                  raise ValueError('Unable to execute command "{}"'.format(command))
              cli_output.setdefault(command, {})
              cli_output[command] = output
  
          return cli_output
docs: Execute a list of commands and return the output in a dictionary format using the command
          as the key.
  
          Example input:
          ['show clock', 'show calendar']
  
          Output example:
          {   'show calendar': u'22:02:01 UTC Thu Feb 18 2016',
              'show clock': u'*22:01:51.165 UTC Thu Feb 18 2016'}