code: public boolean canContain(int parent, int child) {
      if (nofeatureElements.get(parent)) {
        // It's hard to interrogate a browser about the behavior of
        // <noscript> in scriptless mode using JavaScript, and the
        // behavior of <noscript> is more dangerous when in that mode,
        // so we hardcode that mode here as a worst case assumption.
        return true;
      }
  
      return child == TEXT_NODE
          ? canContainText(parent)
          : canContain.get(parent, child);
    }
docs: True if parent can directly contain child.