old_contents: import platform, sys
  
  if platform.system() == 'Windows': # pragma: no cover
      WIN = True
  else: # pragma: no cover
      WIN = False
  
  # True if we are running on Python 3.
  PY2 = sys.version_info[0] == 2
  
  if not PY2: # pragma: no cover
      string_type = str
      unicode_text = str
      byte_string = bytes
      from urllib.parse import urlencode as url_encode
      from urllib.parse import quote as url_quote
      from urllib.parse import unquote as url_unquote
      from urllib.request import url2pathname
  
      def u_(s):
          return str(s)
  
      def bytes_(s):
          return str(s).encode('ascii', 'strict')
  else:
      string_type = basestring
      unicode_text = unicode
      byte_string = str
      from urllib import urlencode as url_encode
      from urllib import quote as url_quote
      from urllib import unquote as url_unquote
      from urllib import url2pathname
  
      def u_(s):
          return unicode(s, 'utf-8')
  
      def bytes_(s):
          return str(s)
  
  def im_func(f):
      if not PY2: # pragma: no cover
          return getattr(f, '__func__', None)
      else:
          return getattr(f, 'im_func', None)
  
  def default_im_func(f):
      if not PY2: # pragma: no cover
          return getattr(f, '__func__', f)
      else:
          return getattr(f, 'im_func', f)
  
  def im_self(f):
      if not PY2: # pragma: no cover
          return getattr(f, '__self__', None)
      else:
          return getattr(f, 'im_self', None)
  
  def im_class(f):
      if not PY2: # pragma: no cover
          self = im_self(f)
          if self is not None:
              return self.__class__
          else:
              return None
      else:
          return getattr(f, 'im_class', None)
  
  def with_metaclass(meta, base=object):
      """Create a base class with a metaclass."""
      return meta("NewBase", (base,), {})
  
  if not PY2: # pragma: no cover
      import builtins
      exec_ = getattr(builtins, "exec")
  
      def reraise(tp, value, tb=None):
          if value.__traceback__ is not tb:
              raise value.with_traceback(tb)
          raise value
  
  else: # pragma: no cover
      def exec_(code, globs=None, locs=None):
          """Execute code in a namespace."""
          if globs is None:
              frame = sys._getframe(1)
              globs = frame.f_globals
              if locs is None:
                  locs = frame.f_locals
              del frame
          elif locs is None:
              locs = globs
          exec("""exec code in globs, locs""")
  
      exec_("""def reraise(tp, value, tb=None):
      raise tp, value, tb
  """)
  
new_contents: import platform, sys
  
  if platform.system() == 'Windows': # pragma: no cover
      WIN = True
  else: # pragma: no cover
      WIN = False
  
  # True if we are running on Python 3.
  PY2 = sys.version_info[0] == 2
  
  if not PY2: # pragma: no cover
      string_type = str
      unicode_text = str
      byte_string = bytes
  else:
      string_type = basestring
      unicode_text = unicode
      byte_string = str
  
subject: Remove unused compatibility functions from TG