code: @Override
      public Map<String, String> getUserDefinedVariableDefaults() {
          HashMap<String, String> userDefinedVariables = new HashMap<String, String>();
          for (Map.Entry<String, ConfigVariable> entry : configVariables.entrySet()) {
              ConfigVariable var = entry.getValue();
              if (var.getValue() == null && var.getDefaultValue() != null) {
                  userDefinedVariables.put(var.getName(), var.getDefaultValue());
              }
          }
          return userDefinedVariables;
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.config.xml.ConfigVariables#getUserDefinedVariableDefaults()