svoid test_positionalTokenIndex2_filter() {
  PositionalTokenIndex2 idx = positionalTokenIndex2_wordTok(tlft([[
    you are here
    what is this
    hello world
    hello you
    hello my friend
  ]]));
  printStruct(idx);
  assertEqualsVerbose(ll("you are here"), 
    positionalTokenIndex2_filter_wordTok(idx, "you * *"));
  assertEqualsVerbose(ll("hello world"),
    positionalTokenIndex2_filter_wordTok(idx, "* world"));
  assertEqualsVerbose(ll("hello world", "hello you"),
    positionalTokenIndex2_filter_wordTok(idx, "hello *"));
  assertEqualsVerbose(ll("what is this"),
    positionalTokenIndex2_filter_wordTok(idx, "* is this"));
  assertEqualsVerbose(ll(),
    positionalTokenIndex2_filter_wordTok(idx, "* * is"));
}