@ConfigAttributeChecker(name = START_LOCATOR)
  protected String checkStartLocator(String value) {
    if (value != null && value.trim().length() > 0) {
      // throws IllegalArgumentException if string is malformed
      DistributionLocatorId.unmarshal(value);
    }
    return value;
  }
Provides an implementation of <code>DistributionConfig</code> that knows how to read the
configuration file.
<p>
Note that if you add a property to this interface, you should update the
{@link AbstractConfig#sameAs} method and the
{@link DistributionConfigImpl#DistributionConfigImpl(DistributionConfig) copy constructor}.
geode-core/src/main/java/org/apache/geode/distributed/internal/AbstractDistributionConfig.java