code: def restore_byte_a0(byts):
      """
      Some mojibake has been additionally altered by a process that said "hmm,
      byte A0, that's basically a space!" and replaced it with an ASCII space.
      When the A0 is part of a sequence that we intend to decode as UTF-8,
      changing byte A0 to 20 would make it fail to decode.
  
      This process finds sequences that would convincingly decode as UTF-8 if
      byte 20 were changed to A0, and puts back the A0. For the purpose of
      deciding whether this is a good idea, this step gets a cost of twice
      the number of bytes that are changed.
  
      This is used as a step within `fix_encoding`.
      """
      byts = A_GRAVE_WORD_RE.sub(b"\xc3\xa0 ", byts)
  
      def replacement(match):
          "The function to apply when this regex matches."
          return match.group(0).replace(b"\x20", b"\xa0")
  
      return ALTERED_UTF8_RE.sub(replacement, byts)
  
imports: import codecs
  import html
  import re
  import warnings
  import ftfy
  from ftfy.chardata import ALTERED_UTF8_RE, C1_CONTROL_RE, CONTROL_CHARS, DOUBLE_QUOTE_RE, HTML_ENTITIES, HTML_ENTITY_RE, LIGATURES, LOSSY_UTF8_RE, SINGLE_QUOTE_RE, UTF8_DETECTOR_RE, WIDTH_MAP
  from ftfy.badness import is_bad
label_desc: Use image node_id 16 for calling a global function with example usage: restore_byte_a0(byts) and returns: ALTERED_UTF8_RE, match