code: public com.google.api.ads.adwords.axis.v201809.cm.AdRotationMode getAdRotationMode() {
          return adRotationMode;
      }
docs: Gets the adRotationMode value for this AdGroupAdRotationMode.
  
  @return adRotationMode   * <span class="constraint CampaignType">This field may only be
  set to OPTIMIZE for campaign channel subtype UNIVERSAL_APP_CAMPAIGN.</span>
  <span class="constraint CampaignType">This field may only be set to
  the values: OPTIMIZE, ROTATE_FOREVER.</span>