anchor.diff:  /// These tests check that the test cases match what ICU produces. They are not
   /// testing the package:intl implementation, they only help verify consistent
   /// behaviour across platforms.
  -// @dart=2.9
   
   @TestOn("!browser")
   @Tags(['ffi'])
  
positive.code: }
  
  void runICUTests(
      {int systemIcuVersion = null,
      String specialIcuLib = null,
      List<String> skipLocales = null}) {
    if (!setupICU(
        systemIcuVersion: systemIcuVersion, specialIcuLibPath: specialIcuLib)) {
      return;
  
negative.code:   final cErrorCode = allocate<Int32>(count: 1);
    cErrorCode.value = 0;
    final uformatter =
        unumf_openForSkeletonAndLocale!(cSkeleton, -1, cLocale, cErrorCode);
    free(cSkeleton);
    free(cLocale);
    var errorCode = cErrorCode.value;
    expect(errorCode, lessThanOrEqualTo(0),
        reason: u_errorName!(errorCode).toString());
    final uresult = unumf_openResult!(cErrorCode);
    errorCode = cErrorCode.value;
    // Try to improve this once dart:ffi has extension methods:
    expect(errorCode, lessThanOrEqualTo(0),
        reason: u_errorName!(errorCode).toString());
  
    // // Format a double:
    // unumf_formatDouble(uformatter, 5142.3, uresult, &ec);
    // if (U_FAILURE(ec)) { return; }
    if (number is double) {
      unumf_formatDouble!(uformatter, number, uresult, cErrorCode);
    } else {
      unumf_formatInt!(uformatter, number as int, uresult, cErrorCode);
    }
    errorCode = cErrorCode.value;
    expect(errorCode, lessThanOrEqualTo(0),
        reason: u_errorName!(errorCode).toString());
  
    // // Export the string to a malloc'd buffer:
    // int32_t len = unumf_resultToString(uresult, NULL, 0, &ec);
  