def testExtendStringWithIterable(self, message_module):
    """Test extending repeated string fields with iterable."""
    m = message_module.TestAllTypes()
    self.assertSequenceEqual([], m.repeated_string)
    m.repeated_string.extend(MessageTest.TestIterable([]))
    self.assertSequenceEqual([], m.repeated_string)
    m.repeated_string.extend(MessageTest.TestIterable(['']))
    self.assertSequenceEqual([''], m.repeated_string)
    m.repeated_string.extend(MessageTest.TestIterable(['1', '2']))
    self.assertSequenceEqual(['', '1', '2'], m.repeated_string)
    m.repeated_string.extend(MessageTest.TestIterable(['3', '4']))
    self.assertSequenceEqual(['', '1', '2', '3', '4'], m.repeated_string)