code: @Override
    public JobMasterClientContext build() {
      if (mMasterInquireClient == null) {
        mMasterInquireClient = MasterInquireClient.Factory.createForJobMaster(mContext.getConf());
      }
      return new JobMasterClientContext(mContext, mMasterInquireClient);
    }
docs: Builds the configuration, creating an instance of {@link MasterInquireClient} if none is
  specified.
  
  @return a {@link JobMasterClientContext}