return new NullFriendlyComparator<>();
  }

  private static final class NullFriendlyComparator<T> implements Comparator<T>, Serializable {
    @Override
    public int compare(T left, T right) {
      return String.valueOf(left).compareTo(String.valueOf(right));
    }
  }

  static int compareOrThrow(Comparable left, Comparable right) {
    return left.compareTo(right);
  }

  /** Needed to serialize sorted collections of Ranges. */
  private static class RangeLexOrdering extends Ordering<Range<?>> implements Serializable {
    static final Ordering<?> INSTANCE = new RangeLexOrdering();

    @Override
    public int compare(Range<?> left, Range<?> right) {
      return ComparisonChain.start()

    };


    /**
     * This is an alternative to the <code>java.lang.Integer.toHexString</code>
     * method. It is an efficient relative that also will pad the left side so
     * that the result is <code>size</code> digits.
     * 
     * @param val
     * @param size
     * @return hex string
     */
    public static String toHexString ( int val, int size ) {

"           <div class=\"wistia_responsive_wrapper\" style=\"height:100%;left:0;position:absolute;top:0;width:100%;\"> \n" +
"             <div class=\"wistia_embed wistia_async_$2 seo=true videoFoam=true\" style=\"height:100%;position:relative;width:100%\"> \n" +
"              <div class=\"wistia_swatch\" style=\"height:100%;left:0;opacity:0;overflow:hidden;position:absolute;top:0;transition:opacity 200ms;width:100%;\"> \n" +

   * during which the {@code RateLimiter} smoothly ramps up its rate, until it reaches its maximum
   * rate at the end of the period (as long as there are enough requests to saturate it). Similarly,
   * if the {@code RateLimiter} is left <i>unused</i> for a duration of {@code warmupPeriod}, it
   * will gradually return to its "cold" state, i.e. it will go through the same warming up process
   * as when it was first created.
   *

25A0..25EF    ; valid                  ;      ; NV8    # 1.1  BLACK SQUARE..LARGE CIRCLE
25F0..25F7    ; valid                  ;      ; NV8    # 3.0  WHITE SQUARE WITH UPPER LEFT QUADRANT..WHITE CIRCLE WITH UPPER RIGHT QUADRANT
25F8..25FF    ; valid                  ;      ; NV8    # 3.2  UPPER LEFT TRIANGLE..LOWER RIGHT TRIANGLE

### The callback path expression

The callback *path* can have an <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md#key-expression" class="external-link" target="_blank">OpenAPI 3 expression</a> that can contain parts of the original request sent to *your API*.

In this case, it's the `str`:

```Python

		return err
	}
	defer ch.Close()

	eventData, eErr := target.store.Get(key)
	if eErr != nil {
		// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
		// Such events will not exist and wouldve been already been sent successfully.
		if os.IsNotExist(eErr) {
			return nil
		}
		return eErr
	}

	if err := target.send(eventData, ch, confirms); err != nil {

		}
		if ok {
			extractedSignedHeaders[http.CanonicalHeaderKey(header)] = val
			continue
		}
		switch header {
		case "expect":
			// Golang http server strips off 'Expect' header, if the
			// client sent this as part of signed headers we need to
			// handle otherwise we would see a signature mismatch.
			// `aws-cli` sets this as part of signed headers.
			//
			// According to

   * during which the {@code RateLimiter} smoothly ramps up its rate, until it reaches its maximum
   * rate at the end of the period (as long as there are enough requests to saturate it). Similarly,
   * if the {@code RateLimiter} is left <i>unused</i> for a duration of {@code warmupPeriod}, it
   * will gradually return to its "cold" state, i.e. it will go through the same warming up process
   * as when it was first created.
   *