How to use the pygubu.stockimage.StockImage.register_from_dir function in pygubu

modulename = fname[:-3]
            try:
                importlib.import_module(modulename)
            except Exception as e:
                logger.exception(e)
                msg = _("Failed to load custom widget module: \n'{0}'")
                msg = msg.format(path)
                messagebox.showerror(_('Error'), msg)

#Initialize images
DESIGNER_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_DIR = os.path.join(DESIGNER_DIR, "images")
StockImage.register_from_dir(IMAGES_DIR)
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '22x22'), '22x22-')
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '16x16'), '16x16-')


class StatusBarHandler(logging.Handler):
    def __init__(self, tklabel, level=logging.NOTSET):
        super(StatusBarHandler, self).__init__(level)
        self.tklabel = tklabel
        self._clear = True
        self._cb_id = None

    def emit(self, record):
        try:
            msg = self.format(record)
            if not self._clear and self._cb_id is not None:
                self.tklabel.after_cancel(self._cb_id)
            self._clear = False

if dirname not in sys.path:
                sys.path.append(dirname)
            modulename = fname[:-3]
            try:
                importlib.import_module(modulename)
            except Exception as e:
                logger.exception(e)
                msg = _("Failed to load custom widget module: \n'{0}'")
                msg = msg.format(path)
                messagebox.showerror(_('Error'), msg)

#Initialize images
DESIGNER_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_DIR = os.path.join(DESIGNER_DIR, "images")
StockImage.register_from_dir(IMAGES_DIR)
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '22x22'), '22x22-')
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '16x16'), '16x16-')


class StatusBarHandler(logging.Handler):
    def __init__(self, tklabel, level=logging.NOTSET):
        super(StatusBarHandler, self).__init__(level)
        self.tklabel = tklabel
        self._clear = True
        self._cb_id = None

    def emit(self, record):
        try:
            msg = self.format(record)
            if not self._clear and self._cb_id is not None:

if fname.endswith('.py'):
            if dirname not in sys.path:
                sys.path.append(dirname)
            modulename = fname[:-3]
            try:
                importlib.import_module(modulename)
            except Exception as e:
                logger.exception(e)
                msg = _("Failed to load custom widget module: \n'{0}'")
                msg = msg.format(path)
                messagebox.showerror(_('Error'), msg)

#Initialize images
DESIGNER_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_DIR = os.path.join(DESIGNER_DIR, "images")
StockImage.register_from_dir(IMAGES_DIR)
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '22x22'), '22x22-')
StockImage.register_from_dir(
    os.path.join(IMAGES_DIR, 'widgets', '16x16'), '16x16-')


class StatusBarHandler(logging.Handler):
    def __init__(self, tklabel, level=logging.NOTSET):
        super(StatusBarHandler, self).__init__(level)
        self.tklabel = tklabel
        self._clear = True
        self._cb_id = None

    def emit(self, record):
        try:
            msg = self.format(record)

try:
    import tkinter as tk
    import tkinter.ttk as ttk
except:
    import Tkinter as tk
    import ttk

from pygubu.stockimage import StockImage, StockImageException
from pygubu.widgets.scrollbarhelper import ScrollbarHelper


FILE_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_DIR = os.path.join(FILE_DIR, "..", "images", "widgets", "propertyeditor")
IMAGES_DIR = os.path.abspath(IMAGES_DIR)
StockImage.register_from_dir(IMAGES_DIR)


class PropertyEditor(ttk.Frame):
    def __init__(self, master=None, **kw):
        self._variable = tk.StringVar()
        self._initvalue = None
        self.value = ''
        ttk.Frame.__init__(self, master, **kw)
        self._create_ui()

    def _create_ui(self):
        pass

    def _validate(self):
        return True

import tkinter.ttk as ttk
    import tkinter.font
except:
    import Tkinter as tk
    import ttk
    import tkFont
    tk.font = tkFont

from pygubu.stockimage import StockImage, StockImageException
from pygubudesigner.widgets.propertyeditor import *

RE_FONT = re.compile("(?P\{\w+(\w|\s)*\}|\w+)\s?(?P-?\d+)?\s?(?P\{\w+(\w|\s)*\}|\w+)?")
FILE_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_DIR = os.path.join(FILE_DIR, "..", "images", "widgets", "fontentry")
IMAGES_DIR = os.path.abspath(IMAGES_DIR)
StockImage.register_from_dir(IMAGES_DIR)

PREDEFINED_FONTS = [
    'TkDefaultFont', 'TkTextFont', 'TkFixedFont',
    'TkMenuFont', 'TkHeadingFont', 'TkCaptionFont',
    'TkSmallCaptionFont', 'TkIconFont', 'TkTooltipFont']
WIN_FONTS = (
    'system', 'ansi', 'device', 'systemfixed', 'ansifixed', 'oemfixed')
MAC_FONTS = (
    'system','application','menu',
    'systemSystemFont', 'systemEmphasizedSystemFont', 'systemSmallSystemFont',
    'systemSmallEmphasizedSystemFont', 'systemApplicationFont',
    'systemLabelFont', 'systemViewsFont', 'systemMenuTitleFont',
    'systemMenuItemFont', 'systemMenuItemMarkFont', 'systemMenuItemCmdKeyFont',
    'systemWindowTitleFont', 'systemPushButtonFont',
    'systemUtilityWindowTitleFont', 'systemAlertHeaderFont',
    'systemToolbarFont', 'systemMiniSystemFont', 'systemDetailSystemFont',