old_contents: from lab_node import LabNode
  
  
  class Asr(LabNode):
  
      def cmd(self, cmd):
          return NotImplementedError
  
new_contents: from lab_node import LabNode
  
  
  class Asr(LabNode):
      def cmd(self, command):
          from fabric.api import settings, run
  
          with settings(host_string='{user}@{ip}'.format(user=self._username, ip=self._ip), password=self._password, connection_attempts=50, warn_only=False):
              return run(command, shell=False)
  
subject: implement ASr.cmd