fixed

Author: octaviansima

src/main/scala/edu/berkeley/cs/rise/opaque/Utils.scala

@@ -1262,7 +1262,7 @@ object Utils extends Logging {
           case LeftAnti => tuix.JoinType.LeftAnti
           case Cross => tuix.JoinType.Cross
           // scalastyle:off
-          case ExistenceJoin(_) => tuix.JoinType.Existence
+          case ExistenceJoin(_) => ???
           case NaturalJoin(_) => ???
           case UsingJoin(_, _) => ???
           // scalastyle:on