custom/modules/MODULE-NAME/clients/base/views/record/record.js

Extending Record View to customize prefill when a user copies a record.js

({
    //The below jsdoc was copied from base RecordView controller in Sugar 7.2
    extendsFrom: 'RecordView',
    /**
     * Called when current record is being duplicated to allow customization of
     * fields that will be copied into new record.
     *
     * Override to setup the fields on this bean prior to being displayed in
     * Create dialog.
     *
     * @param {Object} prefill Bean that will be used for new record.
     * @template
     */
    setupDuplicateFields: function(prefill){
        var duplicateBlackList = ["id", "status", "custom_field_c"];
        _.each(duplicateBlackList, function(field){
            if(field && prefill.has(field)){
                //set blacklist field to the default value if exists
                if (!_.isUndefined(prefill.fields[field]) && !_.isUndefined(prefill.fields[field].default)) {
                    prefill.set(field, prefill.fields[field].default);
                } else {
                    prefill.unset(field);
                }
            }
        });
    }
})

If the function is already present in the parent module, how can i override the parent? how can i just call the child functions to change the field value alone.