code: function configure(config) {
      config = config || {};
      logger.debug('configuring adapters', _.keys(config).join(','));
      _.extend(adapterConfig, _.clone(config));
  
      logger.debug('configuring builtin adapters');
      _.each(BUILTIN_ADAPTERS, function(adapter) {
          adapterConfig[adapter] = {
              path: path.resolve(__dirname, '../adapters/' + adapter),
              builtin: true
          };
      });
  }
docs: Add configuration for the specified adapters but don't initialize them until they are actually used.