code: public void setBuiltInDeliveryRateType(com.google.api.ads.admanager.axis.v201805.DeliveryRateType builtInDeliveryRateType) {
          this.builtInDeliveryRateType = builtInDeliveryRateType;
      }
docs: Sets the builtInDeliveryRateType value for this ProposalLineItemConstraints.
  
  @param builtInDeliveryRateType   * The built-in delivery rate type for the created {@link ProposalLineItem}.
  
  <p>This attribute is read-only.