old_contents: import sys
  
  if sys.hexversion < 0x02070000:
      import unittest2 as unittest
  else:
      import unittest
  
  from hypothesis import given, example
  from hypothesis.extra.datetime import datetimes
  
  from calexicon.calendars import ProlepticGregorianCalendar, JulianCalendar 
  from calexicon.dates import DateWithCalendar, InvalidDate
  
  class CalendarTest(unittest.TestCase):
      calendar = None
  
      def check_valid_date(self, year, month, day):
          d = self.calendar.date(year, month, day)
          self.assertIsNotNone(d)
          self.assertEqual(d.calendar, self.calendar.__class__)
  
      def check_invalid_date(self, year, month, day):
          self.assertRaises(InvalidDate, lambda : self.calendar.date(year, month, day))
  
      @given(datetimes(timezones=[]))
      def test_date_strings(self, dt):
          if self.calendar is None:
              return
          d = dt.date()
          dc = self.calendar.from_date(d)
          self.assertIsNotNone(dc.__str__())
  
      @given(datetimes(timezones=[]))
      def test_date_strings(self, dt):
          if self.calendar is None:
              return 
          d = dt.date()
          dc = self.calendar.from_date(d)
          self.assertIsNotNone(dc.native_representation())
  
      def display_string_comparison(self, year, month, day, expected):
          d = self.calendar.date(year, month, day)
          self.assertEqual(d.__str__(), expected)
  
  
new_contents: import sys
  
  if sys.hexversion < 0x02070000:
      import unittest2 as unittest
  else:
      import unittest
  
  from hypothesis import given, example
  from hypothesis.extra.datetime import datetimes
  
  from calexicon.calendars import ProlepticGregorianCalendar, JulianCalendar 
  from calexicon.dates import DateWithCalendar, InvalidDate
  
  class CalendarTest(unittest.TestCase):
      calendar = None
  
      def check_valid_date(self, year, month, day):
          d = self.calendar.date(year, month, day)
          self.assertIsNotNone(d)
          self.assertEqual(d.calendar, self.calendar.__class__)
  
      def check_invalid_date(self, year, month, day):
          self.assertRaises(InvalidDate, lambda : self.calendar.date(year, month, day))
  
      @given(datetimes(timezones=[]))
      def test_date_strings(self, dt):
          if self.calendar is None:
              return
          d = dt.date()
          dc = self.calendar.from_date(d)
          self.assertIsNotNone(dc.__str__())
  
      @given(datetimes(timezones=[]))
      def test_native_representation(self, dt):
          if self.calendar is None:
              return 
          d = dt.date()
          dc = self.calendar.from_date(d)
          self.assertIsNotNone(dc.native_representation())
  
      def display_string_comparison(self, year, month, day, expected):
          d = self.calendar.date(year, month, day)
          self.assertEqual(d.__str__(), expected)
  
  
subject: Change name of test to avoid collision