How to use the easygui.boxes.multi_fillable_box.MultiBox function in easygui

if fieldValues[i].strip() == "":
                    errmsg += ('"%s" is a required field.\n\n' % fieldNames[i])
            if errmsg == "":
                break # no problems found
            fieldValues = multenterbox(errmsg, title, fieldNames, fieldValues)

        print("Reply was: %s" % str(fieldValues))

    :param str msg: the msg to be displayed.
    :param str title: the window title
    :param list fields: a list of fieldnames.
    :param list values: a list of field values
    :return: String
    """
    if run:
        mb = MultiBox(msg, title, fields, values, mask_last=False,
                      callback=callback)
        reply = mb.run()
        return reply
    else:
        mb = MultiBox(msg, title, fields, values, mask_last=False,
                      callback=callback)
        return mb

fieldNames, fieldValues)

        print("Reply was: %s" % str(fieldValues))

    """
    if run:
        mb = MultiBox(msg, title, fields, values, mask_last=True,
                      callback=callback)

        reply = mb.run()

        return reply

    else:

        mb = MultiBox(msg, title, fields, values, mask_last=True,
                      callback=callback)

        return mb

while 1:
            if fieldValues is None: break
            errmsg = ""
            for i in range(len(fieldNames)):
                if fieldValues[i].strip() == "":
                    errmsg = errmsg + ('"%s" is a required field.\n\n' %
                     fieldNames[i])
                if errmsg == "": break # no problems found
            fieldValues = multpasswordbox(errmsg, title,
              fieldNames, fieldValues)

        print("Reply was: %s" % str(fieldValues))

    """
    if run:
        mb = MultiBox(msg, title, fields, values, mask_last=True,
                      callback=callback)

        reply = mb.run()

        return reply

    else:

        mb = MultiBox(msg, title, fields, values, mask_last=True,
                      callback=callback)

        return mb

print("Reply was: %s" % str(fieldValues))

    :param str msg: the msg to be displayed.
    :param str title: the window title
    :param list fields: a list of fieldnames.
    :param list values: a list of field values
    :return: String
    """
    if run:
        mb = MultiBox(msg, title, fields, values, mask_last=False,
                      callback=callback)
        reply = mb.run()
        return reply
    else:
        mb = MultiBox(msg, title, fields, values, mask_last=False,
                      callback=callback)
        return mb