Store target separately in child class

Author: dungba88

lucene/core/src/java/org/apache/lucene/search/KnnFloatVectorQuery.java

@@ -47,7 +47,7 @@ public class KnnFloatVectorQuery extends AbstractKnnVectorQuery {
 
   private static final TopDocs NO_RESULTS = TopDocsCollector.EMPTY_TOPDOCS;
 
-  final float[] target;
+  private final float[] target;
 
   /**
    * Find the <code>k</code> nearest documents to the target vector according to the vectors in the

lucene/core/src/java/org/apache/lucene/search/TwoPhaseKnnVectorQuery.java

@@ -36,6 +36,7 @@ public class TwoPhaseKnnVectorQuery extends KnnFloatVectorQuery {
 
   private final int originalK;
   private final double oversample;
+  private final float[] target;
 
   /**
    * Find the <code>k</code> nearest documents to the target vector according to the vectors in the
@@ -55,6 +56,7 @@ public TwoPhaseKnnVectorQuery(
     if (oversample < 0) {
       throw new IllegalArgumentException("oversample must be non-negative, got " + oversample);
     }
+    this.target = target;
     this.originalK = k;
     this.oversample = oversample;
   }