@RequiresRestart(RequiresRestart.RestartScope.SYSTEM)
    @JsonPropertyDescription(
            "The maximum size that the pool is allowed to reach, including both idle and in-use connections. " +
                    COMMON_CONN_POOL_DESC)
    @Min(0)
    public int getMaxPoolSize() {
        return maxPoolSize;
    }
Merges the non-null values of other into this. If other is null return this.
stroom-config/stroom-config-common/src/main/java/stroom/config/common/ConnectionPoolConfig.java