K k = (K) key;
        return function.apply(k);
      } else {
        return null;
      }
    }

    @Override
    public @Nullable V remove(@Nullable Object key) {
      if (backingSet().remove(key)) {
        @SuppressWarnings("unchecked") // unsafe, but Javadoc warns about it
        K k = (K) key;
        return function.apply(k);
      } else {
        return null;
      }
    }

    Function<String, String> internerFunction =
        Interners.asFunction(Interners.<String>newStrongInterner());

    assertSame(canonical, internerFunction.apply(canonical));
    assertSame(canonical, internerFunction.apply(not));
  }

  public void testNullPointerExceptions() {
    new NullPointerTester().testAllPublicStaticMethods(Interners.class);
  }

  public void testConcurrencyLevel_zero() {

            return fileIndex;
        }
    }

    // Functional helpers for concise parameterized tests
    private interface IntGetter {
        int apply(FileEntry e);
    }

    private interface LongGetter {
        long apply(FileEntry e);
    }

    // --- Mockito-based interaction tests ---

    @Test
    @DisplayName("Mocked FileEntry returns stubbed values and verifies interactions")

   */
  fun escapeForUri(vararg codePoints: Int) =
    apply {
      uriEscapedCodePoints.append(String(*codePoints))
    }

  /**
   * Configure code points to be stripped in conversion to `java.net.URI`. That class is more
   * strict than the others.
   */
  fun stripForUri(vararg codePoints: Int) =
    apply {
      uriStrippedCodePoints.append(String(*codePoints))
    }

    this.ordering = checkNotNull(ordering);
  }

  @Override
  public int compare(@ParametricNullness F left, @ParametricNullness F right) {
    return ordering.compare(function.apply(left), function.apply(right));
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object == this) {
      return true;
    }
    if (object instanceof ByFunctionOrdering) {

    this.ordering = checkNotNull(ordering);
  }

  @Override
  public int compare(@ParametricNullness F left, @ParametricNullness F right) {
    return ordering.compare(function.apply(left), function.apply(right));
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object == this) {
      return true;
    }
    if (object instanceof ByFunctionOrdering) {

   * any unpaired carriage return or line feed characters with a CR+LF pair</a> on any non-file
   * inputs before escaping them with this escaper.
   *
   * <p>When escaping a String, the following rules apply:
   *
   * <ul>
   *   <li>The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain
   *       the same.
   *   <li>The special characters ".", "-", "*", and "_" remain the same.

        @Override
        public Optional<?> apply(@Nullable Object obj) {
          return Optional.fromNullable(obj);
        }
      };

  private static final Function<Optional<?>, @Nullable Object> OPTIONAL_TO_NULLABLE =
      new Function<Optional<?>, @Nullable Object>() {
        @Override
        public @Nullable Object apply(Optional<?> optional) {
          return optional.orNull();
        }

5536):String.fromCharCode(n>>10|55296,1023&n|56320))},M=function(){V()},R=J(function(e){return!0===e.disabled&&fe(e,"fieldset")},{dir:"parentNode",next:"legend"});try{k.apply(oe=ae.call(ye.childNodes),ye.childNodes),oe[ye.childNodes.length].nodeType}catch(e){k={apply:function(e,t){me.apply(e,ae.call(t))},call:function(e){me.apply(e,ae.call(arguments,1))}}}function I(t,e,n,r){var i,o,a,s,u,l,c,f=e&&e.ownerDocument,p=e?e.nodeType:9;if(n=n||[],"string"!=typeof t||!t||1!==p&&9!==p&&11!==p)return n;i...

        for (T input : inputs) {
          A newAccum = collector.supplier().get();
          collector.accumulator().accept(newAccum, input);
          accum = collector.combiner().apply(accum, newAccum);
        }
        return accum;
      }
    },
    /** Get one accumulator for each element and merge the accumulators right-to-left. */
    MERGE_RIGHT_ASSOCIATIVE {
      @Override