HostAddress getHostAddress(HostAddress hostAddress) throws UnknownHostException {
    HostAddress thisLocator;
    if (hostAddress != null && !StringUtils.isEmpty(hostAddress.getHostName())) {
      thisLocator = hostAddress;
    } else {
      thisLocator = new HostAddress(LocalHostUtil.getLocalHost());
    }
    return thisLocator;
  }
Start a distributed system whose life cycle is managed by this locator. When the locator is
stopped, this distributed system will be disconnected. If a distributed system already exists,
this method will have no affect.

@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/distributed/internal/InternalLocator.java