code: public void setActivityAssociations(com.google.api.ads.admanager.axis.v201805.LineItemActivityAssociation[] activityAssociations) {
          this.activityAssociations = activityAssociations;
      }
docs: Sets the activityAssociations value for this LineItemSummary.
  
  @param activityAssociations   * This attribute is required and meaningful only if the {@link
  LineItem#costType} is {@link
  CostType.CPA}.