public Builder setUnwalkablePolygon(
          int index, org.bwapi.proxy.messages.TerrainMessages.Polygon.Builder builderForValue) {
        if (unwalkablePolygonBuilder_ == null) {
          ensureUnwalkablePolygonIsMutable();
          unwalkablePolygon_.set(index, builderForValue.build());
          onChanged();
        } else {
          unwalkablePolygonBuilder_.setMessage(index, builderForValue.build());
        }
        return this;
      }