code: public com.google.api.ads.admanager.axis.v201805.FrequencyCap[] getBuiltInFrequencyCaps() {
          return builtInFrequencyCaps;
      }
docs: Gets the builtInFrequencyCaps value for this ProposalLineItemConstraints.
  
  @return builtInFrequencyCaps   * The built-in frequency caps for the created {@link ProposalLineItem}.
  
  <p>This attribute is read-only.