class_docstr: Set of elements retaining the insertion order
  All new elements are appended to the end of the set.
class_docstr_tok: ["Set","of","elements","retaining","the","insertion","order","All","new","elements","are","appended","to","the","end","of","the","set","."]
code: def __init__(self, keys: tp.Optional[tp.Iterable[X]] = None) -> None:
      self._data: "collections.OrderedDict[X, int]" = (
          collections.OrderedDict()
      )
      self._global_index = (
          0  # keep track of insertion global index if need be
      )
      if keys is not None:
          for key in keys:
              self.add(key)
  
imports: import os
  import site
  import glob
  import ctypes
  import time
  import inspect
  import warnings
  import itertools
  import contextlib
  import collections
  import typing
  import numpy
  from nevergrad.common import sphere
label_desc: Use image node_id 1 to create a new OrderedSet object from inherited base classes: tp.MutableSet with example: obj = OrderedSet(keys)