rsively(opt_model) {
      const numericNames = new Set();

      // Aggregate descendants's numerics recursively and gather children's
      // numeric names.
      this.children.forEach(function(child) {
        child.aggregateNumericsRecursively(opt_model);
        for (const [item, value] of Object.entries(child.numerics)) {
          numericNames.add(item, value);
        }
      }, this);

      // Aggregate children's numerics.
      numericNames.forEach(function(numericName) {
        if (numericNam