docstr: Whether or not pre-releases as a whole are allowed.
  
  This can be set to either ``True`` or ``False`` to explicitly enable or disable
  prereleases or it can be set to ``None`` (the default) to use default semantics.
docstr_tok: ["Whether","or","not","pre-releases","as","a","whole","are","allowed",".","This","can","be","set","to","either","``","True","``","or","``","False","``","to","explicitly","enable","or","disable","prereleases","or","it","can","be","set","to","``","None","``","(","the","default",")","to","use","default","semantics","."]
code: def prereleases(self) -> Optional[bool]:
      """Whether or not pre-releases as a whole are allowed.
  
      This can be set to either ``True`` or ``False`` to explicitly enable or disable
      prereleases or it can be set to ``None`` (the default) to use default semantics.
      """
  
imports: import abc
  import itertools
  import re
  from typing import Callable, Iterable, Iterator, List, Optional, Set, Tuple, TypeVar, Union
  from .utils import canonicalize_version
  from .version import Version
label_desc: Use image node_id 4 for calling the BaseSpecifier obj's underlying member method code with example usage: obj.prereleases() without return types