code: def _parse(self, stream, context, path):
          
          start = stream.tell()
          read_bytes = ""
          if self.max_length:
              read_bytes = stream.read(self.max_length)
          else:
              read_bytes = stream.read()
          skip = read_bytes.find(self.find) + len(self.find)
          stream.seek(start + skip)
          return skip
docs: Parse stream to find a given byte string.