New omod - location of properties file

I have created a new omod (bahmnitest) for some specific purpose. I want to use properties file. but the following line throws error “Can’t find bundle for base name bahmnitest”

ResourceBundle bahmnitestbundle = ResourceBundle.getBundle("bahmnitest");

Where should be saved? I tried saving it in /opt/openmrs, /opt/openmrs/modules, /opt/openmrs/bahmnitest but still getting the same error.