anchor.diff:    ///   conditionalUri*
     /// ;
     /// ```
  -  Token parseConditionalUris(Token token) {
  -    // TODO(brianwilkerson): Rename to `parseConditionalUriStar`?
  +  Token parseConditionalUriStar(Token token) {
       listener.beginConditionalUris(token.next);
       int count = 0;
       while (optional('if', token.next)) {
  
positive.code:     listener.beginImport(importKeyword);
      token = ensureLiteralString(importKeyword);
      Token uri = token;
      token = parseConditionalUris(token);
      token = parseImportPrefixOpt(token);
      token = parseCombinatorStar(token).next;
      if (optional(';', token)) {
  
negative.code:     assert(optional('export', exportKeyword));
      listener.beginExport(exportKeyword);
      token = ensureLiteralString(exportKeyword);
      token = parseConditionalUriStar(token);
      token = parseCombinatorStar(token);
      token = ensureSemicolon(token);
      listener.endExport(exportKeyword, token);
  