old_contents: import datetime
  import decimal
  
  from django.test import TestCase
  from django.utils import timezone
  
  from ..utils import convert_tstamp, convert_amount_for_api
  
  
  class TestTimestampConversion(TestCase):
  
      def test_conversion_without_field_name(self):
          stamp = convert_tstamp(1365567407)
          self.assertEquals(
              stamp,
              datetime.datetime(2013, 4, 10, 4, 16, 47, tzinfo=timezone.utc)
          )
  
      def test_conversion_with_field_name(self):
          stamp = convert_tstamp({"my_date": 1365567407}, "my_date")
          self.assertEquals(
              stamp,
              datetime.datetime(2013, 4, 10, 4, 16, 47, tzinfo=timezone.utc)
          )
  
      def test_conversion_with_invalid_field_name(self):
          stamp = convert_tstamp({"my_date": 1365567407}, "foo")
          self.assertEquals(
              stamp,
              None
          )
  
      def test_conversion_with_field_name_but_none(self):
          stamp = convert_tstamp({"my_date": None}, "my_date")
          self.assertEquals(
              stamp,
              None
          )
  
      def test_jpy_amount_not_converted_to_cents(self):
          expected = 1000
          actual = convert_amount_for_api(decimal.Decimal("1000"), "jpy")
          self.assertEquals(expected, actual)
  
      def test_usd_amount_converted_to_cents(self):
          expected = 1000
          actual = convert_amount_for_api(decimal.Decimal("10.00"), "usd")
          self.assertEquals(expected, actual)
  
new_contents: import datetime
  import decimal
  
  from django.test import TestCase
  from django.utils import timezone
  
  from ..utils import convert_tstamp, convert_amount_for_api, convert_amount_for_db
  
  
  class TestTimestampConversion(TestCase):
  
      def test_conversion_without_field_name(self):
          stamp = convert_tstamp(1365567407)
          self.assertEquals(
              stamp,
              datetime.datetime(2013, 4, 10, 4, 16, 47, tzinfo=timezone.utc)
          )
  
      def test_conversion_with_field_name(self):
          stamp = convert_tstamp({"my_date": 1365567407}, "my_date")
          self.assertEquals(
              stamp,
              datetime.datetime(2013, 4, 10, 4, 16, 47, tzinfo=timezone.utc)
          )
  
      def test_conversion_with_invalid_field_name(self):
          stamp = convert_tstamp({"my_date": 1365567407}, "foo")
          self.assertEquals(
              stamp,
              None
          )
  
      def test_conversion_with_field_name_but_none(self):
          stamp = convert_tstamp({"my_date": None}, "my_date")
          self.assertEquals(
              stamp,
              None
          )
  
  
  class ConvertAmountForDBTests(TestCase):
  
      def test_convert_amount_for_db(self):
          expected = decimal.Decimal("9.99")
          actual = convert_amount_for_db(999)
          self.assertEquals(expected, actual)
  
      def test_convert_amount_for_db_zero_currency(self):
          expected = decimal.Decimal("999")
          actual = convert_amount_for_db(999, currency="jpy")
          self.assertEquals(expected, actual)
  
      def test_convert_amount_for_db_none_currency(self):
          expected = decimal.Decimal("9.99")
          actual = convert_amount_for_db(999, currency=None)
          self.assertEquals(expected, actual)
  
  
  class ConvertAmountForApiTests(TestCase):
  
      def test_convert_amount_for_api(self):
          expected = 999
          actual = convert_amount_for_api(decimal.Decimal("9.99"))
          self.assertEquals(expected, actual)
  
      def test_convert_amount_for_api_zero_currency(self):
          expected = 999
          actual = convert_amount_for_api(decimal.Decimal("999"), currency="jpy")
          self.assertEquals(expected, actual)
  
      def test_convert_amount_for_api_none_currency(self):
          expected = 999
          actual = convert_amount_for_api(decimal.Decimal("9.99"), currency=None)
          self.assertEquals(expected, actual)
  
subject: Add tests for utils