_add (key, optionsList) {
    this._keyClients[key] = optionsList.map(
      ({
        configKey,
        cluster,
        namespace,
        options
      }) => {
        const client = this._getApollo(options)
        // ctrip-apollo will manage duplication of cluster name
        .cluster(cluster)
        .namespace(namespace)

        this._associateClientAndKey(client, configKey, key)

        return {
          client,
          configKey,
          options
        }
      }
    )
  }
// - optionsList `Array<object>` apollo config key name
optionsList `Array` apollo config key name
optionsList ` Array ` apollo config key name
_add (key, optionsList) {
    this._keyClients[key] = optionsList.map(
      ({
        configKey,
        cluster,
        namespace,
        options
      }) => {
        const client = this._getApollo(options)
        .cluster(cluster)
        .namespace(namespace)
        this._associateClientAndKey(client, configKey, key)
        return {
          client,
          configKey,
          options
        }
      }
    )
  }
_add ( key , optionsList ) { this . _keyClients [ key ] = optionsList . map ( ( { configKey , cluster , namespace , options } ) => { const client = this . _getApollo ( options ) . cluster ( cluster ) . namespace ( namespace ) this . _associateClientAndKey ( client , configKey , key ) return { client , configKey , options } } ) }
optionsList `Array<object>` apollo config key name
optionsList ` Array<object > ` apollo config key name
// ctrip-apollo will manage duplication of cluster name