return a == null ? null : checkNotNull(doForward(a));
    } else {
      return unsafeDoForward(a);
    }
  }

  @Nullable A correctedDoBackward(@Nullable B b) {
    if (handleNullAutomatically) {
      // TODO(kevinb): we shouldn't be checking for a null result at runtime. Assert?
      return b == null ? null : checkNotNull(doBackward(b));
    } else {
      return unsafeDoBackward(b);
    }
  }

  /*

        if (expected == 0) {
          assertWithMessage(x + ", " + y).that(actual).isEqualTo(expected);
        } else if (expected < 0) {
          assertWithMessage(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")")
              .that(actual < 0)
              .isTrue();
        } else {
          assertWithMessage(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")")
              .that(actual > 0)

	}
	if len(f.ops) == 0 {
		return 0, io.EOF
	}
	s, ok := f.ops[0].(string)
	if !ok {
		return 0, errors.New("unexpected Read operation")
	}

	n := copy(b, s)
	if len(s) > n {
		f.ops[0] = s[n:]
	} else {
		f.ops = f.ops[1:]
	}
	f.pos += int64(len(b))
	return n, nil
}

func (f *testFile) Write(b []byte) (int, error) {
	if len(b) == 0 {
		return 0, nil
	}
	if len(f.ops) == 0 {

          FactoryMethodReturnsNullException {
    if (cls.isEnum()) {
      T[] constants = cls.getEnumConstants();
      if (constants != null && constants.length > 0) {
        return constants[0];
      } else {
        return null;
      }
    }
    TypeToken<T> type = TypeToken.of(cls);
    List<ParameterNotInstantiableException> paramErrors = new ArrayList<>();

  * Avoid spurious ELB listener recreation - ignore case when matching protocol ([#47391](https://github.com/kubernetes/kubernetes/pull/47391), [@justinsb](https://github.com/justinsb))

      @Nullable Object[] localAlternatingKeysAndValues;
      int localSize = size;
      if (valueComparator == null) {
        localAlternatingKeysAndValues = alternatingKeysAndValues;
      } else {
        if (entriesUsed) {
          alternatingKeysAndValues = Arrays.copyOf(alternatingKeysAndValues, 2 * size);
        }
        localAlternatingKeysAndValues = alternatingKeysAndValues;

            final String[] defaultSortValues = fessConfig.getDefaultSortValues(getUserBean());
            if (defaultSortValues.length == 1) {
                form.sort = defaultSortValues[0];
            } else if (defaultSortValues.length >= 2) {
                final StringBuilder sortValueSb = new StringBuilder();
                final Set<String> sortFieldNames = new HashSet<>();

    CacheTesting.checkValidState(cache);
  }

  /**
   * Tests that when a single entry exceeds the segment's max weight, the new entry is immediately
   * evicted and nothing else.
   */
  public void testEviction_maxWeight_entryTooBig() {
    CountingRemovalListener<Integer, Integer> removalListener = countingRemovalListener();
    IdentityLoader<Integer> loader = identityLoader();

# Handling Errors { #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.

		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)
	}