old_contents: from .generic import GrammarTest
  
  def test_np():
      grammar = GrammarTest('grammars/test_np.fcfg',
          'grammars/nounphrase.sample', 
          'grammars/nounphrase.sample.negative')
      grammar.check_positive()
      grammar.check_negative()
  
  def test_subject():
      grammar = GrammarTest('grammars/test_subject.fcfg',
          'grammars/subjectphrase.sample',
          'grammars/subjectphrase.sample.negative')
      grammar.check_positive()
      grammar.check_negative()
  
  def test_object():
      grammar = GrammarTest('grammars/test_object.fcfg',
          'grammars/object.sample',
          'grammars/object.sample.negative')
      grammar.check_positive()
      grammar.check_negative()
  
new_contents: from .generic import GrammarTest
  
  def add_grammar(grammar, positive_sample, negative_sample):
      grammar = GrammarTest(grammar, positive_sample,
          negative_sample)
      grammar.check_positive()
      grammar.check_negative()
  
  def test_np():
      add_grammar('grammars/test_np.fcfg',
          'grammars/nounphrase.sample', 
          'grammars/nounphrase.sample.negative')
  
  def test_subject():
      add_grammar('grammars/test_subject.fcfg',
          'grammars/subjectphrase.sample',
          'grammars/subjectphrase.sample.negative')
  
  def test_object():
      add_grammar('grammars/test_object.fcfg',
          'grammars/object.sample',
          'grammars/object.sample.negative')
  
subject: Refactor grammar tests to be easily extensible