public void setHostname(String hostname) {
    this.hostname = hostname;
  }
Create a {@link MockDataNodeId} object from given {@code ports}, {@code mountPaths}, {@code dataCenter}.
@param ports Ports associated with server on node.
@param mountPaths Mount paths for replicas on node.
@param dataCenter Name of datacenter.
ambry-test-utils/src/main/java/com/github/ambry/clustermap/MockDataNodeId.java