getCollectionNames example

        // configuration entity imports. We only need to ensure that simple         // configuration is created when the extension is installed.         $storage = $this->getSourceStorage();
        $prefix = $name . '.';
      }

      // Gets profile storages to search for overrides if necessary.       $profile_storages = $this->getProfileStorages($name);

      // Gather information about all the supported collections.       $collection_info = $this->configManager->getConfigCollectionInfo();
      foreach ($collection_info->getCollectionNames() as $collection) {
        $config_to_create = $this->getConfigToCreate($storage, $collection, $prefix, $profile_storages);
        if ($name == $this->drupalGetProfile()) {
          // If we're installing a profile ensure simple configuration that           // already exists is excluded as it will have already been written.           // This means that if the configuration is changed by something else           // during the install it will not be overwritten again.           $existing_configuration = array_filter($this->getActiveStorages($collection)->listAll(), function D$config_name) {
            return !$this->configManager->getEntityTypeIdByName($config_name);
          });
          $config_to_create = array_diff_key($config_to_create, array_flip($existing_configuration));
        }