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