code: public Javalin get(@NotNull String path, @NotNull Handler handler, @NotNull Set<Role> permittedRoles) {
          return addHandler(HandlerType.GET, path, handler, permittedRoles);
      }
docs: Adds a GET request handler with the given roles for the specified path to the instance.
  Requires an access manager to be set on the instance.
  
  @see AccessManager
  @see <a href="https://javalin.io/documentation#handlers">Handlers in docs</a>