How to use the ecl.common.cliutils.env function in ecl

def completion_cache(self, cache_type, obj_class, mode):
        """
        The completion cache store items that can be used for bash
        autocompletion, like UUIDs or human-friendly IDs.

        A resource listing will clear and repopulate the cache.

        A resource create will append to the cache.

        Delete is not handled because listings are assumed to be performed
        often enough to keep the cache reasonably up-to-date.
        """
        # NOTE(wryan): This lock protects read and write access to the
        # completion caches
        with self.cache_lock:
            base_dir = cliutils.env('BEARCLIENT_UUID_CACHE_DIR',
                                    default="~/.bearclient")

            # NOTE(sirp): Keep separate UUID caches for each username +
            # endpoint pair
            username = cliutils.env('OS_USERNAME', 'BEAR_USERNAME')
            url = cliutils.env('OS_URL', 'BEAR_URL')
            uniqifier = hashlib.md5(username.encode('utf-8') +
                                    url.encode('utf-8')).hexdigest()

            cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))

            try:
                os.makedirs(cache_dir, 0o755)
            except OSError:
                # NOTE(kiall): This is typically either permission denied while
                #              attempting to create the directory, or the

A resource listing will clear and repopulate the cache.

        A resource create will append to the cache.

        Delete is not handled because listings are assumed to be performed
        often enough to keep the cache reasonably up-to-date.
        """
        # NOTE(wryan): This lock protects read and write access to the
        # completion caches
        with self.cache_lock:
            base_dir = cliutils.env('BEARCLIENT_UUID_CACHE_DIR',
                                    default="~/.bearclient")

            # NOTE(sirp): Keep separate UUID caches for each username +
            # endpoint pair
            username = cliutils.env('OS_USERNAME', 'BEAR_USERNAME')
            url = cliutils.env('OS_URL', 'BEAR_URL')
            uniqifier = hashlib.md5(username.encode('utf-8') +
                                    url.encode('utf-8')).hexdigest()

            cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))

            try:
                os.makedirs(cache_dir, 0o755)
            except OSError:
                # NOTE(kiall): This is typically either permission denied while
                #              attempting to create the directory, or the
                #              directory already exists. Either way, don't
                #              fail.
                pass

            resource = obj_class.__name__.lower()

A resource create will append to the cache.

        Delete is not handled because listings are assumed to be performed
        often enough to keep the cache reasonably up-to-date.
        """
        # NOTE(wryan): This lock protects read and write access to the
        # completion caches
        with self.cache_lock:
            base_dir = cliutils.env('BEARCLIENT_UUID_CACHE_DIR',
                                    default="~/.bearclient")

            # NOTE(sirp): Keep separate UUID caches for each username +
            # endpoint pair
            username = cliutils.env('OS_USERNAME', 'BEAR_USERNAME')
            url = cliutils.env('OS_URL', 'BEAR_URL')
            uniqifier = hashlib.md5(username.encode('utf-8') +
                                    url.encode('utf-8')).hexdigest()

            cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))

            try:
                os.makedirs(cache_dir, 0o755)
            except OSError:
                # NOTE(kiall): This is typically either permission denied while
                #              attempting to create the directory, or the
                #              directory already exists. Either way, don't
                #              fail.
                pass

            resource = obj_class.__name__.lower()
            filename = "%s-%s-cache" % (resource, cache_type.replace('_', '-'))