code: def enabled_for_op(self, opdef):
      if r_util.is_r_script(opdef.name):
          return True, "operation is an R script"
      return False, "operation is not an R script"
  
imports: import logging
  import os
  import yaml
  import guild
  from guild import config
  from guild import guildfile
  from guild import model
  from guild import model_proxy
  from guild import plugin
  from .None import r_util
label_desc: Use image node_id 2 for calling the RScriptPlugin obj's underlying member method code with example usage: obj.enabled_for_op(opdef) and returns: False,  str, True,  str