void (@NotNull MavenProject aggregator, @NotNull MavenProject module) { withWriteLock(() -> { List<MavenProject> modules = myAggregatorToModuleMapping.get(aggregator); if (modules == null) { modules = new ArrayList<>(); myAggregatorToModuleMapping.put(aggregator, modules); } modules.add(module); myModuleToAggregatorMapping.put(module, aggregator); }); }