code: public void setAdvertiser(com.google.api.ads.admanager.axis.v201902.ProposalCompanyAssociation advertiser) {
          this.advertiser = advertiser;
      }
docs: Sets the advertiser value for this Proposal.
  
  @param advertiser   * The advertiser, to which this {@code Proposal} belongs, and
  a set of
  {@link Contact} objects associated with the advertiser.
  The
  {@link ProposalCompanyAssociation#type} of this attribute
  should be
  {@link ProposalCompanyAssociationType#ADVERTISER}.
  This attribute is
  required when the proposal turns into an order, and
  its
  {@link ProposalCompanyAssociation#companyId} will
  be copied to
  {@link Order#advertiserId}.
  This attribute becomes readonly once the {@code Proposal}
  has been pushed.