_runCallbacksFoundInTheSettingsObject() { //FIXME test this
        // Loops through the this.settings object (option array) to find the following
        for (const key in this.settings) {
            if (Object.prototype.hasOwnProperty.call(this.settings, key)) {
                const value = this.settings[key];

                if (typeof value === 'function') {
                    this.settings[key] = value(this, key);
                } else {
                    // Calls the attached function from the html5 data. For instance: <tag data-currency-symbol="functionName"></tag>
                    let htmlAttribute = '';
                    if (key in this.domElement.dataset) {
                        htmlAttribute = this.domElement.dataset[key];
                    }

                    htmlAttribute = AutoNumericHelper.camelize(htmlAttribute);
                    if (typeof this.settings[htmlAttribute] === 'function') {
                        this.settings[key] = htmlAttribute(this, key);
                    }
                }
            }
        }
    }
Run any callbacks found in the settings object in order to set the settings value back.
Any parameter can have a callback defined.
The callback takes the current AutoNumeric element as the first argument, and the key name as the second.
@example callback(this, 'currencySymbol')