old_contents: import os
  from .main import main
  
  
  def test_main():
      _this_path = os.path.dirname(os.path.realpath(__file__))
      for (in_file, time_direction) in [('right', 90),
                                        ('up', 0),
                                        ('down', 180)]:
          in_file_name = os.path.join(_this_path, 'test', '{0}.txt'.format(in_file))
          ref_file_name = os.path.join(_this_path, 'test', '{0}.svg'.format(in_file))
          svg = main(1.0, in_file_name, time_direction)
          with open(ref_file_name, 'r') as f:
              reference = f.read()
              assert svg in reference, "failed to test {0}".format(in_file)
  
new_contents: import os
  from .main import main
  
  
  def test_main():
  
      generate_references = os.getenv('GENERATE_REFERENCES', False)
      _this_path = os.path.dirname(os.path.realpath(__file__))
  
      for (in_file, time_direction) in [('right', 90),
                                        ('up', 0),
                                        ('down', 180)]:
          in_file_name = os.path.join(_this_path, 'test', '{0}.txt'.format(in_file))
          ref_file_name = os.path.join(_this_path, 'test', '{0}.svg'.format(in_file))
          svg = main(1.0, in_file_name, time_direction)
          if generate_references:
              with open(ref_file_name, 'w') as f:
                  f.write(svg)
          with open(ref_file_name, 'r') as f:
              reference = f.read()
              assert svg == reference, "failed to test {0}".format(in_file)
  
subject: make it easy to generate new references