code: protected void setSimpleJoin(String[] masterLabels, String masterColumn, String dataColumn,
                                   String masterSeparator, boolean regex, List<String> masterData) {
          this.conf.setInt(SimpleJob.READER_TYPE, SimpleJob.SINGLE_COLUMN_JOIN_READER);
          this.conf.setStrings(SimpleJob.MASTER_LABELS, masterLabels);
          this.conf.set(SimpleJob.JOIN_MASTER_COLUMN, masterColumn);
          this.conf.set(SimpleJob.JOIN_DATA_COLUMN, dataColumn);
          this.masterSeparator = masterSeparator;
          this.conf.setBoolean(SimpleJob.JOIN_REGEX, regex);
          this.masterData = masterData;
      }
docs: Easily supports the Join. To use the setSimpleJoin,
  you must be a size master data appear in the memory of the task.
  @param masterLabels label of master data
  @param masterColumn master column
  @param dataColumn data column
  @param masterSeparator separator
  @param regex master join is regex
  @param masterData master data