public Builder addPoints(
          org.box2d.proto.Box2D.PbVec2.Builder builderForValue) {
        if (pointsBuilder_ == null) {
          ensurePointsIsMutable();
          points_.add(builderForValue.build());
          onChanged();
        } else {
          pointsBuilder_.addMessage(builderForValue.build());
        }
        return this;
      }