old_contents: def check(process_output, judge_output, **kwargs):
      from itertools import izip
      process_lines = filter(None, process_output.split('\n'))
      judge_lines = filter(None, judge_output.split('\n'))
      if len(process_lines) != len(judge_lines):
          return False
      for process_line, judge_line in izip(process_lines, judge_lines):
          if process_line.split() != judge_line.split():
              return False
      return True
  
new_contents: def check(process_output, judge_output, **kwargs):
      from itertools import izip
      process_lines = filter(None, process_output.split('\n'))
      judge_lines = filter(None, judge_output.split('\n'))
      if len(process_lines) != len(judge_lines):
          return False
      for process_line, judge_line in izip(process_lines, judge_lines):
          if process_line.split() != judge_line.split():
              return False
      return True
  
  try:
      from ._checker import standard
  except ImportError as e:
      import sys
      print>> sys.stderr, 'Compile _checker for optimal performance'
  else:
      def check(process_output, judge_output, _checker=standard, **kwargs):
          return _checker(judge_output, process_output)
      del standard
  
subject: Make use of the standard checker in C. #25