public byte getId() {
      return id;
    }
Instantiate by starting a Zk server.
@param tempDirPath the temporary directory string to use.
@param dcName the name of the datacenter.
@param id the id of the datacenter.
@param port the port at which this Zk server should run on localhost.
ambry-test-utils/src/main/java/com/github/ambry/utils/TestUtils.java