if f != nil {
			actual = f(tc.in, tc.arg)
		} else {
			actual = fb(tc.in, []byte(tc.arg))
		}
		report := func(s []byte) string {
			if s == nil {
				return "nil"
			} else {
				return fmt.Sprintf("%q", s)
			}
		}
		if len(actual) != 0 {
			t.Errorf("%s(%s, %q) returned non-empty value", name, report(tc.in), tc.arg)
		} else {
			actualNil := actual == nil
			outNil := tc.out == nil

  public static void assertContains(Iterable<?> actual, Object expected) {
    boolean contained = false;
    if (actual instanceof Collection) {
      contained = ((Collection<?>) actual).contains(expected);
    } else {
      for (Object o : actual) {
        if (equal(o, expected)) {
          contained = true;
          break;
        }
      }
    }

    if (!contained) {

	for remaining := toDel; len(remaining) > 0; toDel = remaining {
		if len(toDel) > maxDeleteList {
			remaining = toDel[maxDeleteList:]
			toDel = toDel[:maxDeleteList]
		} else {
			remaining = nil
		}
		vc, _ := globalBucketVersioningSys.Get(bucket)
		deletedObjs, errs := o.DeleteObjects(ctx, bucket, toDel, ObjectOptions{
			PrefixEnabledFn:  vc.PrefixEnabled,

            // broken SPDY versions of the response cache).
            addLenient("", line.substring(1)) // Empty header name.
          }
          else -> {
            // No header name.
            addLenient("", line)
          }
        }
      }

    /** Add an header line containing a field name, a literal colon, and a value. */

                if (StringUtil.isNotBlank(lang) && lang.length() < 1000) {
                    if (Constants.ALL_LANGUAGES.equalsIgnoreCase(lang)) {
                        langSet.add(Constants.ALL_LANGUAGES);
                    } else {
                        final String normalizeLang = systemHelper.normalizeLang(lang);
                        if (normalizeLang != null) {
                            langSet.add(normalizeLang);
                        }

      return ImmutableSet.copyOf(elements);
    }
  }

  public static class DegeneratedImmutableSetGenerator extends TestStringSetGenerator {
    // Make sure we get what we think we're getting, or else this test
    // is pointless
    @SuppressWarnings("cast")
    @Override
    protected Set<String> create(String[] elements) {
      return (ImmutableSet<String>) ImmutableSet.of(elements[0], elements[0]);
    }

		return nil
	}
	newDisks := make([]StorageAPI, len(disks))
	for index := range errs {
		if errs[index] == nil {
			newDisks[index] = disks[index]
		} else {
			newDisks[index] = nil
		}
	}
	return newDisks
}

// Errors specifically generated by calculatePartSizeFromIdx function.
var (
	errPartSizeZero  = errors.New("Part size cannot be zero")

        # All this is only relevant locally, on GitHub Actions all this is done through
        # artifacts and multiple workflows, so it doesn't matter if directories are
        # removed or not.
    else:
        dist_path = site_path / lang
        shutil.rmtree(dist_path, ignore_errors=True)
    current_dir = os.getcwd()
    os.chdir(lang_path)
    shutil.rmtree(build_site_dist_path, ignore_errors=True)

		return payload, 0, 0, fmt.Errorf("xlMeta: unknown XLv2 header, expected %v, got %v", xlHeader[:4], buf[:4])
	}

	if bytes.Equal(buf[4:8], []byte("1   ")) {
		// Set as 1,0.
		major, minor = 1, 0
	} else {
		major, minor = binary.LittleEndian.Uint16(buf[4:6]), binary.LittleEndian.Uint16(buf[6:8])
	}
	if major > xlVersionMajor {
		return buf[8:], major, minor, fmt.Errorf("xlMeta: unknown major version %d found", major)
	}

# Handling Errors

There are many situations in which you need to notify an error to a client that is using your API.

This client could be a browser with a frontend, a code from someone else, an IoT device, etc.

You could need to tell the client that:

* The client doesn't have enough privileges for that operation.
* The client doesn't have access to that resource.
* The item the client was trying to access doesn't exist.
* etc.