code: public void setBuyerRfp(com.google.api.ads.admanager.axis.v201805.BuyerRfp buyerRfp) {
          this.buyerRfp = buyerRfp;
      }
docs: Sets the buyerRfp value for this Proposal.
  
  @param buyerRfp   * The buyer RFP associated with this {@code Proposal}, which
  is optional. This field will be null
  if the proposal is not initiated from RFP.
  <span class="constraint Applicable">This attribute
  is applicable when:<ul><li>using programmatic guaranteed, not using
  sales management.</li><li>using preferred deals, not using sales management.</li></ul></span>