adding comments instead of removing method

Signed-off-by: Nischal Kumar <[email protected]>

Author: nischalkumar

src/main/java/org/janusgraph/diskstorage/foundationdb/FoundationDBKeyValueStore.java

@@ -15,7 +15,9 @@
 package org.janusgraph.diskstorage.foundationdb;
 
 import com.apple.foundationdb.KeyValue;
+import com.apple.foundationdb.LocalityUtil;
 import com.apple.foundationdb.async.AsyncIterator;
+import com.apple.foundationdb.async.CloseableAsyncIterator;
 import com.apple.foundationdb.directory.DirectorySubspace;
 import com.google.common.base.Preconditions;
 import org.janusgraph.diskstorage.BackendException;
@@ -30,6 +32,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.HashMap;
@@ -250,7 +253,20 @@ public void delete(StaticBuffer key, StoreTransaction txh) throws BackendExcepti
         }
     }
 
+    /* this method is not called within JanusGraph, it's used for bulk access in Spark jobs.
+    For more: Please check: {@link https://github.com/JanusGraph/janusgraph-foundationdb/pull/48#discussion_r498917927}
+     */
+    public List<StaticBuffer> getBoundaryKeys() {
+        List<StaticBuffer> keys = new ArrayList<>();
+        try (CloseableAsyncIterator<byte[]> it = LocalityUtil.getBoundaryKeys(manager.db, db.range().begin, db.range().end)) {
+            it.forEachRemaining(key -> keys.add(getBuffer(db.unpack(key).getBytes(0))));
+        }
+        return keys;
+    }
+
     static StaticBuffer getBuffer(byte[] entry) {
         return new StaticArrayBuffer(entry);
     }
+
+
 }