public Builder depth(final Integer value) {
            this.depth = value;
            return this;
        }
@param value The grouping depth, where 0 is the top level of grouping, or where there is no grouping
@return The {@link Builder}, enabling method chaining
stroom-legacy/stroom-legacy-model_6_1/src/main/java/stroom/legacy/model_6_1/Row.java