code: public com.google.api.ads.adwords.axis.v201809.cm.Label[] getLabels() {
          return labels;
      }
docs: Gets the labels value for this AdGroupCriterion.
  
  @return labels   * Labels that are attached to the AdGroupCriterion. To associate
  an existing {@link Label} to an
  existing {@link AdGroupCriterion}, use {@link AdGroupCriterionService#mutateLabel}
  with ADD
  operator. To remove an associated {@link Label} from
  the {@link AdGroupCriterion}, use
  {@link AdGroupCriterionService#mutateLabel} with REMOVE
  operator. To filter on {@link Label}s,
  use one of {@link Predicate.Operator#CONTAINS_ALL},
  {@link Predicate.Operator#CONTAINS_ANY},
  {@link Predicate.Operator#CONTAINS_NONE} operators
  with a list of {@link Label} ids.
  <span class="constraint CampaignType">This field may
  not be set for campaign channel subtype UNIVERSAL_APP_CAMPAIGN.</span>
  <span class="constraint ReadOnly">This field is read only and will
  be ignored when sent to the API for the following {@link Operator}s:
  REMOVE and SET.</span>