docs: def FindLiteral(self, pattern, data):
      """Search the data for a hit."""
      pattern = utils.Xor(pattern, self.xor_in_key)
  
      offset = 0
      while 1:
        # We assume here that data.find does not make a copy of pattern.
        offset = data.find(pattern, offset)
  
        if offset < 0:
          break
  
        yield (offset, offset + len(pattern))
  
        offset += 1