code: public void setGroups(com.google.api.ads.adwords.axis.v201809.rm.RuleItemGroup[] groups) {
          this.groups = groups;
      }
docs: Sets the groups value for this Rule.
  
  @param groups   * List of rule item groups that defines this rule.
  Rule item groups are ORed together for evaluation
  before version V201705.
  Starting from version V201705, rule item groups are
  grouped together based on
  {@link #getRuleType()} for evaluation.
  <span class="constraint CollectionSize">The minimum
  size of this collection is 1.</span>
  <span class="constraint ContentsDistinct">This field
  must contain distinct elements.</span>
  <span class="constraint ContentsNotNull">This field
  must not contain {@code null} elements.</span>
  <span class="constraint Required">This field is required
  and should not be {@code null}.</span>