code: def test_route_decorator_custom_endpoint_with_dots(app, client):
      bp = flask.Blueprint("bp", __name__)
  
      with pytest.raises(ValueError):
          bp.route("/", endpoint="a.b")(lambda: "")
  
      with pytest.raises(ValueError):
          bp.add_url_rule("/", endpoint="a.b")
  
      def view():
          return ""
  
      view.__name__ = "a.b"
  
      with pytest.raises(ValueError):
          bp.add_url_rule("/", view_func=view)
  
imports: import pytest
  from jinja2 import TemplateNotFound
  from werkzeug.http import parse_cache_control_header
  import flask
label_desc: Use image node_id 15 for calling a global function with example usage: test_route_decorator_custom_endpoint_with_dots(app, client) and returns: str