Remove some dead code in o.e.s.a.b.t.heuristic (#119633) (#119655)

Random finds from auditing code for batched execution:
The builders are unused and the `equals` implementations are unnecessarily verbose, cleaning both up here.

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/ChiSquare.java

@@ -38,10 +38,7 @@ public class ChiSquare extends NXYSignificanceHeuristic {
 
     @Override
     public boolean equals(Object other) {
-        if ((other instanceof ChiSquare) == false) {
-            return false;
-        }
-        return super.equals(other);
+        return other instanceof ChiSquare && super.equals(other);
     }
 
     @Override
@@ -80,17 +77,4 @@ public class ChiSquare extends NXYSignificanceHeuristic {
         return builder;
     }
 
-    public static class ChiSquareBuilder extends NXYSignificanceHeuristic.NXYBuilder {
-        public ChiSquareBuilder(boolean includeNegatives, boolean backgroundIsSuperset) {
-            super(includeNegatives, backgroundIsSuperset);
-        }
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(NAME);
-            super.build(builder);
-            builder.endObject();
-            return builder;
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/GND.java

@@ -46,10 +46,7 @@ public class GND extends NXYSignificanceHeuristic {
 
     @Override
     public boolean equals(Object other) {
-        if ((other instanceof GND) == false) {
-            return false;
-        }
-        return super.equals(other);
+        return other instanceof GND && super.equals(other);
     }
 
     @Override
@@ -99,17 +96,4 @@ public class GND extends NXYSignificanceHeuristic {
         return builder;
     }
 
-    public static class GNDBuilder extends NXYBuilder {
-        public GNDBuilder(boolean backgroundIsSuperset) {
-            super(true, backgroundIsSuperset);
-        }
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(NAME);
-            builder.field(BACKGROUND_IS_SUPERSET.getPreferredName(), backgroundIsSuperset);
-            builder.endObject();
-            return builder;
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/JLHScore.java

@@ -90,10 +90,7 @@ public class JLHScore extends SignificanceHeuristic {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == null || obj.getClass() != getClass()) {
-            return false;
-        }
-        return true;
+        return obj != null && obj.getClass() == getClass();
     }
 
     @Override
@@ -101,12 +98,4 @@ public class JLHScore extends SignificanceHeuristic {
         return getClass().hashCode();
     }
 
-    public static class JLHScoreBuilder implements SignificanceHeuristicBuilder {
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(NAME).endObject();
-            return builder;
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/MutualInformation.java

@@ -40,10 +40,7 @@ public class MutualInformation extends NXYSignificanceHeuristic {
 
     @Override
     public boolean equals(Object other) {
-        if ((other instanceof MutualInformation) == false) {
-            return false;
-        }
-        return super.equals(other);
+        return other instanceof MutualInformation && super.equals(other);
     }
 
     @Override
@@ -119,17 +116,4 @@ public class MutualInformation extends NXYSignificanceHeuristic {
         return builder;
     }
 
-    public static class MutualInformationBuilder extends NXYBuilder {
-        public MutualInformationBuilder(boolean includeNegatives, boolean backgroundIsSuperset) {
-            super(includeNegatives, backgroundIsSuperset);
-        }
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(NAME);
-            super.build(builder);
-            builder.endObject();
-            return builder;
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/NXYSignificanceHeuristic.java

@@ -66,9 +66,7 @@ public abstract class NXYSignificanceHeuristic extends SignificanceHeuristic {
         if (obj == null) return false;
         if (getClass() != obj.getClass()) return false;
         NXYSignificanceHeuristic other = (NXYSignificanceHeuristic) obj;
-        if (backgroundIsSuperset != other.backgroundIsSuperset) return false;
-        if (includeNegatives != other.includeNegatives) return false;
-        return true;
+        return backgroundIsSuperset == other.backgroundIsSuperset && includeNegatives == other.includeNegatives;
     }
 
     @Override
@@ -160,24 +158,10 @@ public abstract class NXYSignificanceHeuristic extends SignificanceHeuristic {
      */
     protected static <T> Function<Object[], T> buildFromParsedArgs(BiFunction<Boolean, Boolean, T> ctor) {
         return args -> {
-            boolean includeNegatives = args[0] == null ? false : (boolean) args[0];
-            boolean backgroundIsSuperset = args[1] == null ? true : (boolean) args[1];
+            boolean includeNegatives = args[0] != null && (boolean) args[0];
+            boolean backgroundIsSuperset = args[1] == null || (boolean) args[1];
             return ctor.apply(includeNegatives, backgroundIsSuperset);
         };
     }
 
-    protected abstract static class NXYBuilder implements SignificanceHeuristicBuilder {
-        protected boolean includeNegatives = true;
-        protected boolean backgroundIsSuperset = true;
-
-        public NXYBuilder(boolean includeNegatives, boolean backgroundIsSuperset) {
-            this.includeNegatives = includeNegatives;
-            this.backgroundIsSuperset = backgroundIsSuperset;
-        }
-
-        protected void build(XContentBuilder builder) throws IOException {
-            builder.field(INCLUDE_NEGATIVES_FIELD.getPreferredName(), includeNegatives)
-                .field(BACKGROUND_IS_SUPERSET.getPreferredName(), backgroundIsSuperset);
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/PercentageScore.java

@@ -56,10 +56,7 @@ public class PercentageScore extends SignificanceHeuristic {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == null || obj.getClass() != getClass()) {
-            return false;
-        }
-        return true;
+        return obj != null && obj.getClass() == getClass();
     }
 
     @Override
@@ -67,12 +64,4 @@ public class PercentageScore extends SignificanceHeuristic {
         return getClass().hashCode();
     }
 
-    public static class PercentageScoreBuilder implements SignificanceHeuristicBuilder {
-
-        @Override
-        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(NAME).endObject();
-            return builder;
-        }
-    }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/heuristic/SignificanceHeuristicBuilder.java

@@ -1,14 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the "Elastic License
- * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
- * Public License v 1"; you may not use this file except in compliance with, at
- * your election, the "Elastic License 2.0", the "GNU Affero General Public
- * License v3.0 only", or the "Server Side Public License, v 1".
- */
-
-package org.elasticsearch.search.aggregations.bucket.terms.heuristic;
-
-import org.elasticsearch.xcontent.ToXContentFragment;
-
-public interface SignificanceHeuristicBuilder extends ToXContentFragment {}