private boolean tagExists(String name, Collection<? extends FunctionTag> tags) {
		FunctionTag tag = getTagForName(name, tags);
		return tag != null;
	}
Returns an immutable tag (the first one found) from the source panel, if one exists. 

@return an immutable tag, or null if not found
@throws UsrException if there's an error retrieving tags in the source panel
Ghidra/Features/Base/src/test.slow/java/ghidra/app/plugin/core/function/tags/FunctionTagPluginTest.java