public Builder addAllNormals(
          java.lang.Iterable<? extends org.box2d.proto.Box2D.PbVec2> values) {
        if (normalsBuilder_ == null) {
          ensureNormalsIsMutable();
          super.addAll(values, normals_);
          onChanged();
        } else {
          normalsBuilder_.addAllMessages(values);
        }
        return this;
      }