docstr: add additional __dir__ for this object 
docstr_tok: ["add","additional","__dir__","for","this","object"]
code: def _dir_additions(self):
      """add additional __dir__ for this object"""
      rv = set()
      for accessor in self._accessors:
          try:
              getattr(self, accessor)
              rv.add(accessor)
          except AttributeError:
              pass
      return rv
  
imports: import warnings
  from pandas.util._decorators import Appender
label_desc: Use image node_id 2 for calling the DirNamesMixin obj's underlying member method code with example usage: obj._dir_additions() and returns: rv