* Returns the given {@code template} string with each occurrence of {@code "%s"} replaced with
   * the corresponding argument value from {@code args}; or, if the placeholder and argument counts
   * do not match, returns a best-effort form of that string. Will not throw an exception under
   * normal conditions.
   *
   * <p><b>Note:</b> For most string-formatting needs, use {@link String#format String.format},

   * Implementations must support such concurrent calls.
   *
   * Note that cancellation is best-effort and that a call may proceed normally after it has been
   * canceled. For example, happy-path events like [requestHeadersStart] and [requestHeadersEnd] may
   * occur after a call is canceled. Typically cancellation takes effect when an expensive I/O
   * operation is required.
   *

   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note
   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   */
  private transient int metadata;

  /** The number of elements contained in the set. */
  private transient int size;

    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED
      --add-opens java.base/java.util=ALL-UNNAMED
      --add-opens java.base/sun.security.jca=ALL-UNNAMED
    </test.add.opens>

    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED
      --add-opens java.base/java.util=ALL-UNNAMED
      --add-opens java.base/sun.security.jca=ALL-UNNAMED
    </test.add.opens>

   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note
   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   *
   * <p>For a new instance, where the arrays above have not yet been allocated, the value of {@code

  }

  public void testPrecomputedOptimizations() {
    // These are testing behavior that's never promised by the API.
    // Some matchers are so efficient that it is a waste of effort to
    // build a precomputed version.
    CharMatcher m1 = is('x');
    assertSame(m1, m1.precomputed());
    assertEquals(m1.toString(), m1.precomputed().toString());

    CharMatcher m2 = anyOf("Az");

 *
 * <p>The tested methods and constructors are invoked -- each time with one parameter being null and
 * the rest not null -- and the test fails if no expected exception is thrown. {@code
 * NullPointerTester} uses best effort to pick non-null default values for many common JDK and Guava
 * types, and also for interfaces and public classes that have public parameter-less constructors.

    available in those versions!


## Version 4.8.0

_2020-07-11_

 *  New: Change `HeldCertificate.Builder` to use its own ASN.1 certificate encoder. This is part
    of our effort to remove the okhttp-tls module's dependency on Bouncy Castle. We think Bouncy
    Castle is great! But it's a large dependency (6.5 MiB) and its security provider feature
    impacts VM-wide behavior.

  private static final CharMatcher QUOTED_TEXT_MATCHER = ascii().and(CharMatcher.noneOf("\"\\\r"));

  /*
   * This matches the same characters as linear-white-space from RFC 822, but we make no effort to
   * enforce any particular rules with regards to line folding as stated in the class docs.
   */
  private static final CharMatcher LINEAR_WHITE_SPACE = CharMatcher.anyOf(" \t\r\n");

  // TODO(gak): make these public?