def METHOD_NAME(
    self,
    protocol_name: str,
    data_fs_subdir: str,
    vfs_dst_path: str,
    src_path=None,
    owner_uid=0,
    group_gid=0,
    perms=0o755,
) -> (SubAbstractFS, subfs.SubFS):
    """
    Method that would be used by protocols to initialize vfs. May be called by each protocol individually. This
    creates a chroot jail sub file system env which makes easier handling. It also creates a data_fs sub file system
    for managing protocol specific uploads.
    :param protocol_name: name of the protocol for which VFS is being created.
    :param data_fs_subdir: sub-folder name within data_fs that would be storing the uploads for later analysis
    :param vfs_dst_path:  protocol specific sub-folder path in the fs.
    :param src_path: Source from where the files are to copied.
    :param owner_uid: UID of a registered user. This is the default owner in the sub file system
    :param group_gid: GID of a existing group.
    :param perms: Default permissions of the sub file system.
    :return: fs object
    **Note:** The owner_uid and group_gid must be already registered with the fs. Otherwise an exception
    would be raised.
    """
    assert isinstance(protocol_name, str) and protocol_name
    assert isinstance(data_fs_subdir, str) and data_fs_subdir
    assert isinstance(vfs_dst_path, str) and vfs_dst_path
    if src_path:
        assert isinstance(src_path, str)
        if not os.path.isdir(src_path):
            logger.error("Protocol directory is not a valid directory.")
            sys.exit(3)
    logger.info(
        "Creating persistent data store for protocol: {}".format(protocol_name)
    )
    # create a sub directory for persistent storage.
    if self.data_fs.isdir(data_fs_subdir):
        sub_data_fs = self.data_fs.opendir(path=data_fs_subdir)
    else:
        sub_data_fs = self.data_fs.makedir(path=data_fs_subdir)
    if protocol_name not in self._conpot_vfs.keys():
        sub_protocol_fs = self.protocol_fs.mount_fs(
            vfs_dst_path, src_path, owner_uid, group_gid, perms
        )
        self._conpot_vfs[protocol_name] = (sub_protocol_fs, sub_data_fs)
    return self._conpot_vfs[protocol_name]