Convert PreservesAll to explicit invalidates=false

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/main/scala/firrtl/passes/RemoveEmpty.scala b/src/main/scala/firrtl/passes/RemoveEmpty.scala
index 2407acb6..eabf667c 100644
--- a/src/main/scala/firrtl/passes/RemoveEmpty.scala
+++ b/src/main/scala/firrtl/passes/RemoveEmpty.scala
@@ -4,14 +4,14 @@ package firrtl
 package passes
 
 import firrtl.ir._
-import firrtl.options.PreservesAll
 import firrtl.stage.Forms
 
-object RemoveEmpty extends Pass with DependencyAPIMigration with PreservesAll[Transform] {
+object RemoveEmpty extends Pass with DependencyAPIMigration {
 
   override def prerequisites = Seq.empty
   override def optionalPrerequisites = Forms.LowFormOptimized
   override def optionalPrerequisiteOf = Forms.ChirrtlEmitters
+  override def invalidates(a: Transform) = false
 
   private def onModule(m: DefModule): DefModule = {
     m match {