code: def _create_conversion_trie(strict):
      
      t = pygtrie.CharTrie()
  
      for beta, uni in _map.BETACODE_MAP.items():
          if strict:
              t[beta] = uni
          else:
              # The order of accents is very strict and weak. Allow for many orders of
              # accents between asterisk and letter or after letter. This does not
              # introduce ambiguity since each betacode token only has one letter and
              # either starts with a asterisk or a letter.
              diacritics = beta[1:]
  
              perms = itertools.permutations(diacritics)
              for perm in perms:
                  perm_str = beta[0] + ''.join(perm)
                  t[perm_str.lower()] = uni
                  t[perm_str.upper()] = uni
  
      return t
docs: Create the trie for betacode conversion.
  
      Args:
      text: The beta code text to convert. All of this text must be betacode.
      strict: Flag to allow for flexible diacritic order on input.
  
      Returns:
      The trie for conversion.