drop final from SoyMsgBundleHandler, people are mocking this
GITHUB_BREAKING_CHANGES=none
@@ -37,7 +37,7 @@ import java.util.regex.Pattern;
*
*/
@Immutable
-public final class SoyMsgBundleHandler {
+public class SoyMsgBundleHandler {
/**
* Options for generating an output messages file.
