function setIntProp(src, dst, propName, minVal, maxVal, def) {
        if (hasProperty(src, propName)) {
            var v = parseInt(src[propName]);
            if(isNaN(v)) return;
            if(minVal != null) {
                if(v < minVal) return;
            }
            if(maxVal != null) {
                if(v > maxVal) return;
            }
            dst[propName] = v;
        } else {
            if(def != undefined) dst[propName] = def;
        }
    }
Helper function for setting integer property values in the MQTT V5 properties object
@param {object} src Source object containing properties
@param {object} dst Destination object to set/add properties
@param {string} propName The property name to set in the Destination object
@param {integer} [minVal] The minimum value. If the src value is less than minVal, it will NOT be set in the destination
@param {integer} [maxVal] The maximum value. If the src value is greater than maxVal, it will NOT be set in the destination
@param {integer} [def] An optional default to set in the destination object if prop is NOT present in the soruce object