public static synchronized ProjectIndexService getIndexFor(Project project) {
		if (project == null || project.isClosed()) {
			return DUMMY;
		}

		ProjectIndexService result = instances.get(project.getProjectLocator());
		if (result == null) {
			result = new ProjectIndexService(project);
			instances.put(project.getProjectLocator(), result);
		}
		return result;
	}
Returns an index for a Project.  Instances returned by this method should not be 
{@link #close() closed} by the caller.

@param project {@link Project} to get index for, or {@code null} for a DUMMY placeholder 
@return {@link ProjectIndexService} instance, never null
Ghidra/Features/Base/src/main/java/ghidra/plugin/importer/ProjectIndexService.java