private static List<SpecRunHistory> loadHistories(List<String> specNames) {
    List<SpecRunHistory> histories = new ArrayList<>(specNames.size());

    for (String name : specNames) {
      SpecRunHistory history = new SpecRunHistory(name);
      try {
        history.loadFromDisk();
      } catch (IOException ignored) {} // history stays empty, so spec will be run early on
      histories.add(history);
    }

    return histories;
  }
Returns the number of features contained in the given specification.
Because Spock allows for the dynamic creation of new features at
specification run time, this number is only an estimate.
spock-core/src/main/java/org/spockframework/runtime/SpecUtil.java