code: private static CustomParameters createCustomParameters(ProductPartitionNode node) {
      Preconditions.checkArgument(
          node.isBiddableUnit(), "Node is not a biddable unit. Custom parameters not supported.");
      CustomParameters customParameters = new CustomParameters();
      List<CustomParameter> parameters = new ArrayList<>();
      for (Entry<String, String> customParamEntry : node.getCustomParameters().entrySet()) {
        CustomParameter customParameter = new CustomParameter();
        customParameter.setKey(customParamEntry.getKey());
        customParameter.setValue(customParamEntry.getValue());
        parameters.add(customParameter);
      }
      customParameters.setParameters(parameters.toArray(new CustomParameter[0]));
      // Always replace all custom parameters. This attribute is ignored on ADD.
      customParameters.setDoReplace(true);
      return customParameters;
    }
docs: Creates an AdWords API {@link CustomParameters} object using the map of custom parameters
  on the node.
  
  @param node the node.