private void endGatewayConflictResolver() {
    Declarable d = createDeclarable();
    if (!(d instanceof GatewayConflictResolver)) {
      throw new CacheXmlException(
          String.format("A %s is not an instance of a GatewayConflictResolver.",
              d.getClass().getName()));
    }
    CacheCreation c = (CacheCreation) stack.peek();
    c.setGatewayConflictResolver((GatewayConflictResolver) d);
  }
When a <code>gateway-conflict-resolver</code> element is encountered, create a new listener for
the <code>Cache</code>.
geode-core/src/main/java/org/apache/geode/internal/cache/xmlcache/CacheXmlParser.java