code: public void setCreativePlaceholders(com.google.api.ads.admanager.axis.v201902.CreativePlaceholder[] creativePlaceholders) {
          this.creativePlaceholders = creativePlaceholders;
      }
docs: Sets the creativePlaceholders value for this BuyerRfp.
  
  @param creativePlaceholders   * A list of inventory sizes in which creatives will be eventually
  served.
  <span class="constraint ReadOnly">This attribute is
  read-only when:<ul><li>using programmatic guaranteed, not using sales
  management.</li><li>using preferred deals, not using sales management.</li></ul></span>