def METHOD_NAME(self) -> None:
    """Reads PluginStorage content from the disk to a dict structure
    :raises .errors.PluginStorageError: when unable to open or read the file
    """
    data: Dict[str, Any] = {}
    filedata = ""
    try:
        with open(self._storagepath, 'r') as fh:
            filedata = fh.read()
    except IOError as e:
        errmsg = "Could not read PluginStorage data file: {0} : {1}".format(
            self._storagepath, str(e))
        if os.path.isfile(self._storagepath):
            # Only error out if file exists, but cannot be read
            logger.error(errmsg)
            raise errors.PluginStorageError(errmsg)
    try:
        data = json.loads(filedata)
    except ValueError:
        if not filedata:
            logger.debug("Plugin storage file %s was empty, no values loaded",
                         self._storagepath)
        else:
            errmsg = "PluginStorage file {0} is corrupted.".format(
                self._storagepath)
            logger.error(errmsg)
            raise errors.PluginStorageError(errmsg)
    self._data = data