use builder, remove primitive, change jackson annotation

src/main/java/in/zapr/druid/druidry/extensions/datasketches/postAggregator/ThetaSketchEstimatePostAggregator.java

@@ -18,29 +18,23 @@
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import in.zapr.druid.druidry.postAggregator.DruidPostAggregator;
+import lombok.Builder;
 import lombok.Getter;
 import lombok.NonNull;
 
 @Getter
+@JsonInclude(JsonInclude.Include.NON_NULL)
 public class ThetaSketchEstimatePostAggregator extends DruidPostAggregator {
 
     private static final String THETA_SKETCH_ESTIMATE_POST_AGGREGATOR_TYPE = "thetaSketchEstimate";
-
     private DruidPostAggregator field;
+    private Integer errorBoundsStdDev;
 
-    @JsonInclude(JsonInclude.Include.NON_DEFAULT)
-    private int errorBoundsStdDev;
-
-    public ThetaSketchEstimatePostAggregator(@NonNull String name,
-                                             @NonNull DruidPostAggregator field) {
-        this.type = THETA_SKETCH_ESTIMATE_POST_AGGREGATOR_TYPE;
-        this.name = name;
-        this.field = field;
-    }
-
-    public ThetaSketchEstimatePostAggregator(@NonNull String name,
-                                             @NonNull DruidPostAggregator field,
-                                             int errorBoundsStdDev) {
+    @Builder
+    public ThetaSketchEstimatePostAggregator(
+            @NonNull String name,
+            @NonNull DruidPostAggregator field,
+            Integer errorBoundsStdDev) {
         this.type = THETA_SKETCH_ESTIMATE_POST_AGGREGATOR_TYPE;
         this.name = name;
         this.field = field;