@Deprecated // @deprecated in favour of {@link HCatTable.#mapKeysTerminatedBy()}. To be removed in Hive 0.16.
    public Builder mapKeysTerminatedBy(char delimiter) {
      return serdeParam(serdeConstants.MAPKEY_DELIM, Character.toString(delimiter));
    }
See <i>row_format</i> element of CREATE_TABLE DDL for Hive.
hcatalog/webhcat/java-client/src/main/java/org/apache/hive/hcatalog/api/HCatCreateTableDesc.java