Find iDempiere OSGi Plugin Interfaces or Extension Points

Here is how I search for iDempiere plugin interfaces:

Update the code to be on the correct branch
- git checkout release-9
search for the following terms and look in the following places:
- Search Service.locator().list
- Search Service.locator().locate
- IEventTopics
  - See IEventTopics.java for list of all topics. Pick the one that looks most appropriate to you and search the code to see how/where it is used.
- Review core.java - this on is important to understand if you are interested in knowing how iDempiere interacts with the OSGi engine.
- Review org.adempiere.webui.Extension classes
- Check all osgi-inf/*.xml files
example searches:
- grep -rni . -e "Service.locator().list" > ~/delme/service_list.txt
- grep -rni . -e "Service.locator().locate" > ~/delme/service_located.txt
- grep -rni . -e IEventTopics > ~/delme/event_topic.txt
  - Note; This search returns every reference (lots of noise).
  - Note: You might be better off searching on a specific event name.
look for examples like the following:
- Service.locator().list(IDisplayTypeFactory.class).getServices();
- Service.locator().locate(IMessageService.class).getService();
- RequestEventHandler.java:61: if (topic.equals(IEventTopics.REQUEST_SEND_EMAIL))