code: public ListRuleGroupsResult withRuleGroups(RuleGroupSummary... ruleGroups) {
          if (this.ruleGroups == null) {
              setRuleGroups(new java.util.ArrayList<RuleGroupSummary>(ruleGroups.length));
          }
          for (RuleGroupSummary ele : ruleGroups) {
              this.ruleGroups.add(ele);
          }
          return this;
      }
docs: <p>
  An array of <a>RuleGroup</a> objects.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setRuleGroups(java.util.Collection)} or {@link #withRuleGroups(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param ruleGroups
  An array of <a>RuleGroup</a> objects.
  @return Returns a reference to this object so that method calls can be chained together.