anchor.diff:      }
       return lintingErrors;
     }
  -  return section.entries.where((entry) => entry is CommentEntry).map((entry) =>
  +  return section.entries.whereType<CommentEntry>().map((entry) =>
         new LintingError(entry.lineNumber, "Comment is on a line by itself."));
   }
   
  
positive.code: /// Checks for duplicate section entries in the body of a section.
  Iterable<LintingError> lintSectionEntryDuplicates(StatusSection section) {
    var errors = <LintingError>[];
    // TODO(whereType): When whereType is supported, use that.
    List<StatusEntry> statusEntries = section.entries
        .where((entry) => entry is StatusEntry)
        .cast<StatusEntry>()
        .toList();
    for (var i = 0; i < statusEntries.length; i++) {
      var entry = statusEntries[i];
  
negative.code: /// ordered alphabetically.
  Iterable<LintingError> lintAlphabeticalOrderingOfPaths(StatusSection section) {
    var entries = section.entries
        .whereType<StatusEntry>()
        .map((entry) => (entry as StatusEntry).path)
        .toList();
    var sortedList = entries.toList()..sort((a, b) => a.compareTo(b));
  