FoundationsConfigurationService.java

private Map<Object, Map<String, C config>> configsMap = new HashMap<>();

public void register(@Nonnull Object plugin, @Nonnull String key, @Nonnull C config) {
        getPluginManager().fromInstance(checkNotNull(plugin, nullTemplate, "plugin")).ifPresent(container -> {
            final String id = container.getId();
            Map<String, C> tempMap;

            if (configsMap.containsKey(id)) {
                tempMap = configsMap.get(id);
            } else {
                tempMap = new HashMap<>();
            }

            if (!tempMap.containsKey(checkNotNull(key, nullTemplate, "key"))) {
                tempMap.put(key, checkNotNull(config, nullTemplate, "config"));
                configsMap.put(plugin, tempMap);
            } else {
                getFoundationsCore().getLogger().info(format(getSysMessages().get().getNode("configurations", "keyAlreadyRegistered").getString(), key));
            }
        });
    }