How to use the node-opcua-data-access.EUInformation function in node-opcua-data-access

dataType: "Range",
                minimumSamplingInterval: 0,
                accessLevel: "CurrentRead | CurrentWrite",
                value: new Variant({
                    dataType: DataType.ExtensionObject, value: new Range(options.instrumentRange)
                }),
                modellingRule: options.modellingRule ? "Mandatory" : undefined
            });

            instrumentRange.on("value_changed",handler);

        }

        if (options.hasOwnProperty("engineeringUnits")) {

            const engineeringUnits = new EUInformation(options.engineeringUnits);
            assert(engineeringUnits instanceof EUInformation, "expecting engineering units");

            // EngineeringUnits  specifies the units for the   DataItem‟s value (e.g., DEGC, hertz, seconds).   The
            // EUInformation   type is specified in   5.6.3.

            const eu = namespace.addVariable({
                propertyOf: variable,
                typeDefinition: "PropertyType",
                browseName: {name:"EngineeringUnits",namespaceIndex:0},
                dataType: "EUInformation",
                minimumSamplingInterval: 0,
                accessLevel: "CurrentRead",
                value: new Variant({
                    dataType: DataType.ExtensionObject, value: engineeringUnits
                }),
                modellingRule: options.modellingRule ? "Mandatory" : undefined

init(this: any) {
                this.euInformation = new EUInformation({});
            },
            parser: {

finish(this: any) {
                this.euInformation = new EUInformation(this.euInformation);
            }
        }

finish: function () {
                this.euInformation = new EUInformation(this.euInformation);
            }
        }