// which contains only the schemes under test.
//
// Without this additional step, when there are schemes available but the user
// only requests schemes that don't exist, first instantiation of the test would
// filter out all the user provided schemes (as they are not registered) but
// subsequent instantiations would return all registered schemes (since the
// vector with the user provided schemes is cleared).

              bool expect_failure = false) {
    DefineT(num_opers, opers, ToOutput(inputs), ToOutput(outputs), output_names,
            expect_failure);
  }

  // Caller must delete[] the returned value
  static const char** ToArray(const std::vector<string>& strs) {
    const char** ptr = nullptr;
    if (!strs.empty()) {
      ptr = new const char*[strs.size()];