code: def shellcmd(self, cmd):
      """Return shell command with given modules loaded."""
      return "module purge && module load {to_load}; {cmd}".format(
          to_load=" ".join(self.names), cmd=cmd
      )
  
label_desc: Use image node_id 2 for calling the EnvModules obj's underlying member method code with example usage: obj.shellcmd(cmd) and returns: str