public void TestClearFieldByDescriptor()
{
TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.CreateBuilder()
.AddExtension(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite, 0);
Assert.AreEqual(1, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
IFieldDescriptorLite f = UnitTestLiteProtoFile.RepeatedInt32ExtensionLite.Descriptor;
builder.ClearField(f);
Assert.AreEqual(0, builder.GetExtensionCount(UnitTestLiteProtoFile.RepeatedInt32ExtensionLite));
}