This application has been instrumented with Elastic APM.
In order to configure this application environment variables should be
used in the configMap of the app.yaml file.
Custom instrumentation begins in the main method in st_app.py with the call
client = Client()
client.begin_transaction('main_page')
and ends with client.end_transaction('main_page')
The sidebar menu and charts are instrumented with custom instrumentations.
The display_sidebar has its internal functions instrumented
with the with notation.
The charts and display_header are instrumented with the annotation method.