diff --git a/lucene/core/src/test/org/apache/lucene/util/TestOfflineSorter.java b/lucene/core/src/test/org/apache/lucene/util/TestOfflineSorter.java
index 005806a3f9e..82e9cef9b88 100644
--- a/lucene/core/src/test/org/apache/lucene/util/TestOfflineSorter.java
+++ b/lucene/core/src/test/org/apache/lucene/util/TestOfflineSorter.java
@@ -27,8 +27,6 @@ import java.util.Arrays;
 import java.util.Comparator;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import org.apache.lucene.util.IOUtils;
-import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.OfflineSorter.BufferSize;
 import org.apache.lucene.util.OfflineSorter.ByteSequencesWriter;
 import org.apache.lucene.util.OfflineSorter.SortInfo;
diff --git a/lucene/sandbox/src/java/org/apache/lucene/bkdtree/BKDTreeWriter.java b/lucene/sandbox/src/java/org/apache/lucene/bkdtree/BKDTreeWriter.java
index 0d14a1e9c88..2194e3d368e 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/bkdtree/BKDTreeWriter.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/bkdtree/BKDTreeWriter.java
@@ -443,19 +443,6 @@ class BKDTreeWriter {
     return indexFP;
   }
 
-  // Called only from assert
-  private boolean directoryIsEmpty(Path in) {
-    try (DirectoryStream<Path> dir = Files.newDirectoryStream(in)) {
-      for (Path path : dir) {
-        assert false: "dir=" + in + " still has file=" + path;
-        return false;
-      }
-    } catch (IOException ioe) {
-      // Just ignore: we are only called from assert
-    }
-    return true;
-  }
-
   /** Sliced reference to points in an OfflineSorter.ByteSequencesWriter file. */
   private static final class PathSlice {
     final LatLonWriter writer;
diff --git a/lucene/sandbox/src/java/org/apache/lucene/rangetree/RangeTreeWriter.java b/lucene/sandbox/src/java/org/apache/lucene/rangetree/RangeTreeWriter.java
index ef9b16696e0..8b81e527926 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/rangetree/RangeTreeWriter.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/rangetree/RangeTreeWriter.java
@@ -386,19 +386,6 @@ class RangeTreeWriter {
     return indexFP;
   }
 
-  // Called only from assert
-  private boolean directoryIsEmpty(Path in) {
-    try (DirectoryStream<Path> dir = Files.newDirectoryStream(in)) {
-      for (Path path : dir) {
-        assert false: "dir=" + in + " still has file=" + path;
-        return false;
-      }
-    } catch (IOException ioe) {
-      // Just ignore: we are only called from assert
-    }
-    return true;
-  }
-
   /** Sliced reference to points in an OfflineSorter.ByteSequencesWriter file. */
   private static final class PathSlice {
     final SliceWriter writer;
diff --git a/lucene/spatial3d/src/java/org/apache/lucene/bkdtree3d/BKD3DTreeWriter.java b/lucene/spatial3d/src/java/org/apache/lucene/bkdtree3d/BKD3DTreeWriter.java
index 02fbe5e5eac..743da8f940f 100644
--- a/lucene/spatial3d/src/java/org/apache/lucene/bkdtree3d/BKD3DTreeWriter.java
+++ b/lucene/spatial3d/src/java/org/apache/lucene/bkdtree3d/BKD3DTreeWriter.java
@@ -452,19 +452,6 @@ class BKD3DTreeWriter {
     return indexFP;
   }
 
-  // Called only from assert
-  private boolean directoryIsEmpty(Path in) {
-    try (DirectoryStream<Path> dir = Files.newDirectoryStream(in)) {
-      for (Path path : dir) {
-        assert false: "dir=" + in + " still has file=" + path;
-        return false;
-      }
-    } catch (IOException ioe) {
-      // Just ignore: we are only called from assert
-    }
-    return true;
-  }
-
   /** Sliced reference to points in an OfflineSorter.ByteSequencesWriter file. */
   private static final class PathSlice {
     final Writer writer;