old_contents: """__future__:  Record of phased-in incompatible language changes.
  
  Each line is of the form:
  
      FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease ")"
  
  where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuples
  of the same form as sys.version_info:
  
      (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
       PY_MINOR_VERSION, # the 1; an int
       PY_MICRO_VERSION, # the 0; an int
       PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
       PY_RELEASE_SERIAL # the 3; an int
      )
  
  OptionalRelease records the first release in which
  
      from __future__ import FeatureName
  
  was accepted.
  
  In the case of MandatoryReleases that have not yet occurred,
  MandatoryRelease predicts the release in which the feature will become part
  of the language.
  
  Else MandatoryRelease records when the feature became part of the language;
  in releases at or after that, modules no longer need
  
      from __future__ import FeatureName
  
  to use the feature in question, but may continue to use such imports.
  
  MandatoryRelease may also be None, meaning that a planned feature got
  dropped.
  
  Instances of class _Feature have two corresponding methods,
  .getOptionalRelease() and .getMandatoryRelease().
  
  No feature line is ever to be deleted from this file.
  """
  
  class _Feature:
      def __init__(self, optionalRelease, mandatoryRelease):
          self.optional = optionalRelease
          self.mandatory = mandatoryRelease
  
      def getOptionalRelease(self):
          """Return first release in which this feature was recognized.
  
          This is a 5-tuple, of the same form as sys.version_info.
          """
  
          return self.optional
  
      def getMandatoryRelease(self):
          """Return release in which this feature will become mandatory.
  
          This is a 5-tuple, of the same form as sys.version_info, or, if
          the feature was dropped, is None.
          """
  
          return self.mandatory
  
      def __repr__(self):
          return "Feature(" + `self.getOptionalRelease()` + ", " + \
                              `self.getMandatoryRelease()` + ")"
  
  nested_scopes = _Feature((2, 1, 0, "beta", 1), (2, 2, 0, "final", 0))
  
new_contents: """Record of phased-in incompatible language changes.
  
  Each line is of the form:
  
      FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease ")"
  
  where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuples
  of the same form as sys.version_info:
  
      (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
       PY_MINOR_VERSION, # the 1; an int
       PY_MICRO_VERSION, # the 0; an int
       PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
       PY_RELEASE_SERIAL # the 3; an int
      )
  
  OptionalRelease records the first release in which
  
      from __future__ import FeatureName
  
  was accepted.
  
  In the case of MandatoryReleases that have not yet occurred,
  MandatoryRelease predicts the release in which the feature will become part
  of the language.
  
  Else MandatoryRelease records when the feature became part of the language;
  in releases at or after that, modules no longer need
  
      from __future__ import FeatureName
  
  to use the feature in question, but may continue to use such imports.
  
  MandatoryRelease may also be None, meaning that a planned feature got
  dropped.
  
  Instances of class _Feature have two corresponding methods,
  .getOptionalRelease() and .getMandatoryRelease().
  
  No feature line is ever to be deleted from this file.
  """
  
  class _Feature:
      def __init__(self, optionalRelease, mandatoryRelease):
          self.optional = optionalRelease
          self.mandatory = mandatoryRelease
  
      def getOptionalRelease(self):
          """Return first release in which this feature was recognized.
  
          This is a 5-tuple, of the same form as sys.version_info.
          """
  
          return self.optional
  
      def getMandatoryRelease(self):
          """Return release in which this feature will become mandatory.
  
          This is a 5-tuple, of the same form as sys.version_info, or, if
          the feature was dropped, is None.
          """
  
          return self.mandatory
  
      def __repr__(self):
          return "Feature(" + `self.getOptionalRelease()` + ", " + \
                              `self.getMandatoryRelease()` + ")"
  
  nested_scopes = _Feature((2, 1, 0, "beta", 1), (2, 2, 0, "final", 0))
  
subject: Remove redundant "__future__:" from module docstring.