@API(status = API.Status.STABLE)
        public @NonNull Builder<C, T> withPermission(final @NonNull String permissionString) {
            return this.withPermission(Permission.of(permissionString));
        }
Create a new builder instance using the given flag permission

@param permissionString Flag permission
@return New builder instance
cloud-core/src/main/java/org/incendo/cloud/parser/flag/CommandFlag.java