code: def writeline(self, fmt, *args):
          
          fmt = self.endian + fmt
          size = struct.calcsize(fmt)
  
          fix = struct.pack(self.endian + 'i', size)
          line = struct.pack(fmt, *args)
  
          self.write(fix)
          self.write(line)
          self.write(fix)
docs: Write `line` (list of objects) with given `fmt` to file. The
          `line` will be chained if object is iterable (except for
          basestrings).