Inventory Plugin Caching, missing Cache Property so self.cache getting not populated from BaseInventoryPlugin on _read_config_data

testing.py

from __future__ import (absolute_import, division, print_function)

__metaclass__ = type

import logging
import json

from ansible.plugins.inventory import BaseInventoryPlugin, Constructable, Cacheable

class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
    NAME = 'testing'

    def __init__(self):
        super(InventoryModule, self).__init__()

    def __populate(self, data):
        for host in data:
            self.inventory.add_host(host)

    def parse(self, inventory, loader, path, cache=False):
        logging.basicConfig(filename='/tmp/ansible_debug.log', level=logging.DEBUG)
        super(InventoryModule, self).parse(inventory, loader, path, cache)
        config_data = self._read_config_data(path=path)


        cache_needs_update = False
        cache_key = self.get_cache_key(path)
        logging.debug("CacheKey: " + cache_key)
        logging.debug("config:" + json.dumps(config_data))
        logging.debug("Cache:" + str(cache))

        if cache:
            try:
                # ERROR: self.cache = NOTHING
                # cache_key is defined
                # looks like something happening in BaseInventoryPlugin._read_config_data
                # so self._options.get('cache') not getting set
                cache_object = self.cache.get(cache_key)
                logging.debug("We LOAD FROM CACHE!")
            except KeyError:
                cache_needs_update = True
        
        if not cache or cache_needs_update:
            results = [
                "MySampleHost"
            ]
        else:
            results = cache_object
        
        self.__populate(results)

        if cache_needs_update or (not cache and self.get_option('cache')):
            self.cache.set(cache_key, results)

testing_inventory.yml

plugin: testing
cache: True