I am having trouble with web2py routes.example.py - error-handling

Question

Hi I would like to ask a question about routes.example.py
My app is called "HelloWorld"
If I use following URL
http://127.0.0.1:8000/helloWorld/default/index
The user is guided to the main page.
I am trying to figure out handling errors.
For example If I have a following URL
http://127.0.0.1:8000/helloWorld/default/index11
I have to handle the error.
Based on my research, I know that I need to work on "routes.example.py"
The following is my work in routes.example.py
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from fileutils import abspath
from languages import read_possible_languages
possible_languages = read_possible_languages(abspath('applications', app))
routers = {
app: dict(
default_language = possible_languages['default'][0],
languages = [lang for lang in possible_languages
if lang != 'default']
)
}
*** above part is given by the web2py***
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default_application = "HelloWorld"
default_controller = "default"
default_function = "index"
routes_onerror = [
('HelloWorld/400', '/HelloWorld/default/login'),
('HelloWorld/*', '/HelloWorld/static/fail.html'),
('*/404', '/HelloWorld/static/cantfind.html'),
('*/*', '/HelloWorld/error/index')
]
I define the default application, default controller and default fuction
Bases on these, I define the error cases in routes_onerror...
Can you tell me that what I am missing?