static void web_replaceFirstWord(Web web, S word1, S word2) {
  for (WebNode node : web_nonRelationNodes(web)) {
    S text = node.text();
    L<S> words = words2(text);
    if (eqic(first(words), word1)) {
      words.set(0, word2);
      web_setText(node, joinWithSpaces(words));
    }
  }
}

Began life as a copy of #1010124