// fn create_user(
origin: T::Origin,
new_user: T::NewUser,
) -> DispatchResult {
let sender = ensure_signed(origin)?;
ensure_owner(&sender)?;
let new_user = new_user.into_inner();
let user_id = Self::next_user_id()?;
let user = User::new(new_user.name, new_user.role);
<Users<T>>::insert(user_id, user);
Self::deposit_event(RawEvent::UserCreated(user_id, new_user.name, new_user.role));
Ok(())
}