openrtb-core/src/main/java/com/google/openrtb/util/OpenRtbUtils.java
@Nullable public static Bid.Builder bidWithId(BidResponse.Builder response, String id) {
    checkNotNull(id);

    for (SeatBid.Builder seatbid : response.getSeatbidBuilderList()) {
      for (Bid.Builder bid : seatbid.getBidBuilderList()) {
        if (id.equals(bid.getId())) {
          return bid;
        }
      }
    }
    return null;
  }
@Nullable public static Bid.Builder bidWithId(BidResponse.Builder response, String id) {
    checkNotNull(id);

    for (SeatBid.Builder seatbid : response.getSeatbidBuilderList()) {
      for (Bid.Builder bid : seatbid.getBidBuilderList()) {
        if (id.equals(bid.getId())) {
          return bid;
        }
      }
    }
    return null;
  }
Finds a bid by ID.

@param id Bid ID, assumed to be unique within the response
@return Matching bid's builder, or {@code null} if not found