/*
 * Copyright 2018-present Red Brick Lane Marketing Solutions Pvt. Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package in.zapr.druid.druidry.aggregator;

import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.NonNull;
import lombok.Setter;

@Getter
@EqualsAndHashCode(callSuper = true)
public class DoubleMaxAggregator extends DruidAggregator {

    private static final String DOUBLE_MAX_TYPE_AGGREGATOR = "doubleMax";

    private String fieldName;

    @Setter
    private String expression;

    public DoubleMaxAggregator(@NonNull String name) {
        this.type = DOUBLE_MAX_TYPE_AGGREGATOR;
        this.name = name;
    }

    public DoubleMaxAggregator(@NonNull String name, @NonNull String fieldName) {
        this.type = DOUBLE_MAX_TYPE_AGGREGATOR;
        this.name = name;
        this.fieldName = fieldName;
    }
    @Builder
    private DoubleMaxAggregator(@NonNull String name, String fieldName, String expression) {

        this.type = DOUBLE_MAX_TYPE_AGGREGATOR;
        this.name = name;
        this.fieldName = fieldName;
        this.expression = expression;

        Preconditions.checkArgument(
                fieldName == null ^ expression == null,
                "Must have a valid, non-null fieldName or expression"
        );
    }
}

@@ -819,16 +819,59 @@
 = true)%0A
+@JsonInclude(JsonInclude.Include.NON_NULL)%0A
 public c

Update src/main/java/in/zapr/druid/druidry/aggregator/DoubleMaxAggregator.java