var finalMD5Bytes []byte
	for _, part := range parts {
		md5Bytes, err := hex.DecodeString(canonicalizeETag(part.ETag))
		if err != nil {
			finalMD5Bytes = append(finalMD5Bytes, []byte(part.ETag)...)
		} else {
			finalMD5Bytes = append(finalMD5Bytes, md5Bytes...)
		}
	}
	s3MD5 := fmt.Sprintf("%s-%d", getMD5Hash(finalMD5Bytes), len(parts))
	return s3MD5
}

// Clean unwanted fields from metadata

    if (element == null) {
      while (iterator.hasNext()) {
        if (iterator.next() == null) {
          return true;
        }
      }
    } else {
      while (iterator.hasNext()) {
        if (element.equals(iterator.next())) {
          return true;
        }
      }
    }
    return false;
  }

  /**

      char c1 = seq.charAt(index++);
      if (c1 < Character.MIN_HIGH_SURROGATE || c1 > Character.MAX_LOW_SURROGATE) {
        // Fast path (first test is probably all we need to do)
        return c1;
      } else if (c1 <= Character.MAX_HIGH_SURROGATE) {
        // If the high surrogate was the last character, return its inverse
        if (index == end) {
          return -c1;
        }

   * implementation.
   */
  protected K standardFirstKey() {
    Entry<K, V> entry = firstEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lastEntry() {
    return delegate().lastEntry();
  }

  /**

<img src="/img/tutorial/custom-response/image01.png">

## Available responses { #available-responses }

Here are some of the available responses.

Keep in mind that you can use `Response` to return anything else, or even create a custom sub-class.

/// note | Technical Details

You could also use `from starlette.responses import HTMLResponse`.

   * implementation.
   */
  protected K standardFirstKey() {
    Entry<K, V> entry = firstEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lastEntry() {
    return delegate().lastEntry();
  }

  /**

      char c1 = seq.charAt(index++);
      if (c1 < Character.MIN_HIGH_SURROGATE || c1 > Character.MAX_LOW_SURROGATE) {
        // Fast path (first test is probably all we need to do)
        return c1;
      } else if (c1 <= Character.MAX_HIGH_SURROGATE) {
        // If the high surrogate was the last character, return its inverse
        if (index == end) {
          return -c1;
        }

                            if ("https".equalsIgnoreCase(forwardedProto)) {
                                cookie.setSecure(true);
                            } else {
                                cookie.setSecure(req.isSecure());
                            }
                        } else {
                            cookie.setSecure(Constants.TRUE.equalsIgnoreCase(secure));
                        }

          pred = curr;
        } else if (pred != null) { // We are unlinking this node and it has a predecessor.
          pred.next = succ;
          if (pred.thread == null) { // We raced with another node that unlinked pred. Restart.
            continue restart;
          }
        } else if (!casWaiters(curr, succ)) { // We are unlinking head

        }
        String keyStr = key.toString();
        if (keyStr.indexOf('_') < 0) {
            keyStr = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, StringUtils.uncapitalize(keyStr));
        } else {
            keyStr = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, keyStr);
        }
        return keyStr;
    }

    @Override
    public int size() {
        return parent.size();
    }