code: def skipline(self):
          
          position = self.tell()
          prefix = self._fix()
          self.seek(prefix, 1)  # skip content
          suffix = self._fix()
  
          if prefix != suffix:
              raise IOError(_FIX_ERROR)
  
          return position, prefix
docs: Skip the next line and returns position and size of line.
          Raises IOError if pre- and suffix of line do not match.