code: def test_error_handler_http_subclass(app):
      class ForbiddenSubclassRegistered(Forbidden):
          pass
  
      class ForbiddenSubclassUnregistered(Forbidden):
          pass
  
      @app.errorhandler(403)
      def code_exception_handler(e):
          assert isinstance(e, Forbidden)
          return "forbidden"
  
      @app.errorhandler(ForbiddenSubclassRegistered)
      def subclass_exception_handler(e):
          assert isinstance(e, ForbiddenSubclassRegistered)
          return "forbidden-registered"
  
      @app.route("/forbidden")
      def forbidden_test():
          raise Forbidden()
  
      @app.route("/forbidden-registered")
      def registered_test():
          raise ForbiddenSubclassRegistered()
  
      @app.route("/forbidden-unregistered")
      def unregistered_test():
          raise ForbiddenSubclassUnregistered()
  
      c = app.test_client()
  
      assert c.get("/forbidden").data == b"forbidden"
      assert c.get("/forbidden-unregistered").data == b"forbidden"
      assert (
          c.get("/forbidden-registered").data == b"forbidden-registered"
      )
  
file_path: flask/tests/test_user_error_handler.py
imports: import pytest
  from werkzeug.exceptions import Forbidden
  from werkzeug.exceptions import HTTPException
  from werkzeug.exceptions import InternalServerError
  from werkzeug.exceptions import NotFound
  import flask
label_desc: Use image node_id 3 for calling a global function with example usage: test_error_handler_http_subclass(app) and returns: str, str