class_docstr: Mapping of file objects to selector keys.
class_docstr_tok: ["Mapping","of","file","objects","to","selector","keys","."]
code: def __init__(self, selector):
      self._selector = selector
  
imports: from abc import ABCMeta, abstractmethod
  from collections import namedtuple
  from collections.abc import Mapping
  import math
  import select
  import sys
label_desc: Use image node_id 1 to create a new _SelectorMapping object from inherited base classes: Mapping with example: obj = _SelectorMapping(selector)