code: def timezone_keys(
      *,
      # allow_alias: bool = True,
      # allow_deprecated: bool = True,
      allow_prefix: bool = True,
  ) -> SearchStrategy[str]:
      """A strategy for :wikipedia:`IANA timezone names <List_of_tz_database_time_zones>`.
  
      As well as timezone names like ``"UTC"``, ``"Australia/Sydney"``, or
      ``"America/New_York"``, this strategy can generate:
  
      - Aliases such as ``"Antarctica/McMurdo"``, which links to ``"Pacific/Auckland"``.
      - Deprecated names such as ``"Antarctica/South_Pole"``, which *also* links to
        ``"Pacific/Auckland"``.  Note that most but
        not all deprecated timezone names are also aliases.
      - Timezone names with the ``"posix/"`` or ``"right/"`` prefixes, unless
        ``allow_prefix=False``.
  
      These strings are provided separately from Tzinfo objects - such as ZoneInfo
      instances from the timezones() strategy - to facilitate testing of timezone
      logic without needing workarounds to access non-canonical names.
  
      .. note::
  
          The :mod:`python:zoneinfo` module is new in Python 3.9, so you will need
          to install the :pypi:`backports.zoneinfo` module on earlier versions.
  
          `On Windows, you will also need to install the tzdata package
          <https://docs.python.org/3/library/zoneinfo.html#data-sources>`__.
  
          ``pip install hypothesis[zoneinfo]`` will install these conditional
          dependencies if and only if they are needed.
  
      On Windows, you may need to access IANA timezone data via the :pypi:`tzdata`
      package.  For non-IANA timezones, such as Windows-native names or GNU TZ
      strings, we recommend using :func:`~hypothesis.strategies.sampled_from` with
      the :pypi:`dateutil <python-dateutil>` package, e.g.
      :meth:`dateutil:dateutil.tz.tzwin.list`.
      """
      # check_type(bool, allow_alias, "allow_alias")
      # check_type(bool, allow_deprecated, "allow_deprecated")
      check_type(bool, allow_prefix, "allow_prefix")
      if zoneinfo is None:  # pragma: no cover
          raise ModuleNotFoundError(
              "The zoneinfo module is required, but could not be imported.  "
              "Run `pip install hypothesis[zoneinfo]` and try again."
          )
  
      available_timezones = (
          "UTC",
          *sorted(zoneinfo.available_timezones()),
      )
  
      # TODO: filter out alias and deprecated names if disallowed
  
      # When prefixes are allowed, we first choose a key and then flatmap to get our
      # choice with one of the available prefixes.  That in turn means that we need
      # some logic to determine which prefixes are available for a given key:
  
      def valid_key(key):
          return key == "UTC" or _valid_key_cacheable(
              zoneinfo.TZPATH, key
          )
  
      # TODO: work out how to place a higher priority on "weird" timezones
      # For details see https://github.com/HypothesisWorks/hypothesis/issues/2414
      strategy = sampled_from(
          [key for key in available_timezones if valid_key(key)]
      )
  
      if not allow_prefix:
          return strategy
  
      def sample_with_prefixes(zone):
          keys_with_prefixes = (zone, f"posix/{zone}", f"right/{zone}")
          return sampled_from(
              [key for key in keys_with_prefixes if valid_key(key)]
          )
  
      return strategy.flatmap(sample_with_prefixes)
  
imports: import datetime
  from calendar import monthrange
  from functools import lru_cache
  from importlib import resources
  from pathlib import Path
  from typing import Optional
  from hypothesis.errors import InvalidArgument
  from hypothesis.internal.validation import check_type, check_valid_interval
  from hypothesis.strategies._internal.core import sampled_from
  from hypothesis.strategies._internal.misc import just, none
  from hypothesis.strategies._internal.strategies import SearchStrategy
  from hypothesis.strategies._internal.utils import defines_strategy
label_desc: Use image node_id 10 for calling a global function with example usage: timezone_keys() and returns: strategy, unknown, strategy, sampled_from