public void codeDefined(Address addr) {
		if (!ignoreChanges && addr != null) {
			instructionTasks.notifyAdded(addr);
		}
	}
Identify external addresses which need to be analyzed
NOTE: This is a convenience method for blockAdded
@param extAddr external address or null for all externals
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/analysis/AutoAnalysisManager.java