code: public void postRegistration(String username, String password, String email, String fullname) {
          ClientResource resource = new ClientResource(Route.REGISTER.url());
  
          Form form = new Form();
          form.add("username", username);
          form.add("password_1", password);
          form.add("password_2", password);
          form.add("email", email);
          form.add("fullname", fullname);
  
          resource.post(form);
      }
docs: Registers a new user for the SC4D LEX
  
  @param username the username for the new user
  @param password the password for the new user
  @param email the e-mail for the new user
  @param fullname the name for the new user (can be blank)