public Builder addUnwalkablePolygon(
          org.bwapi.proxy.messages.TerrainMessages.Polygon.Builder builderForValue) {
        if (unwalkablePolygonBuilder_ == null) {
          ensureUnwalkablePolygonIsMutable();
          unwalkablePolygon_.add(builderForValue.build());
          onChanged();
        } else {
          unwalkablePolygonBuilder_.addMessage(builderForValue.build());
        }
        return this;
      }