def test_can_get_current_time(self):
# Arrange
strategy = TradingStrategy(order_id_tag='001')
# Act
result = strategy.time_now()
# Assert
self.assertEqual(timezone.utc, result.tzinfo)
def test_can_change_clock(self):
# Arrange
clock = TestClock()
strategy = TradingStrategy(order_id_tag='001')
# Act
strategy.change_clock(clock)
# Assert
self.assertEqual(UNIX_EPOCH, strategy.time_now())
self.assertEqual(PositionId('P-19700101-000000-000-001-1'),
strategy.position_id_generator.generate())
