code: public com.google.api.ads.adwords.axis.v201809.cm.BidSource getCpmBidSource() {
          return cpmBidSource;
      }
docs: Gets the cpmBidSource value for this CpmBid.
  
  @return cpmBidSource   * The level (ad group or criterion) at which the bid was set.
  This is applicable
  only at the criteria level.
  <span class="constraint ReadOnly">This field is
  read only and will be ignored when sent to the API.</span>