code: def check_output(self, cmd):
          
          p = self.Popen(cmd, stdout=subprocess.PIPE)
          output, _ = p.communicate()
          if p.returncode != 0:
              raise RemoteCalledProcessError(p.returncode, cmd, self.host, output=output)
          return output
docs: Execute a shell command remotely and return the output.
  
          Simplified version of Popen when you only want the output as a string and detect any errors.