-   [guava-discuss: For open-ended questions and discussion](https://groups.google.com/group/guava-discuss)

## IMPORTANT WARNINGS

1. APIs marked with the `@Beta` annotation at the class or method level
are subject to change. They can be modified in any way, or even
removed, at any time. If your code is a library itself (i.e. it is

 * <p><b>Note:</b> This class is similar to {@link CharEscaper} but with one very important
 * difference. A CharEscaper can only process Java <a
 * href="http://en.wikipedia.org/wiki/UTF-16">UTF16</a> characters in isolation and may not cope
 * when it encounters surrogate pairs. This class facilitates the correct escaping of all Unicode
 * characters.
 *
 * <p>As there are important reasons, including potential security issues, to handle Unicode

   * Configures the given map maker to use weak keys, if possible; does nothing otherwise (i.e., in
   * GWT). This is sometimes acceptable, when only server-side code could generate enough volume
   * that reclamation becomes important.
   */
  @J2ktIncompatible
  static MapMaker tryWeakKeys(MapMaker mapMaker) {
    return mapMaker.weakKeys();
  }

  static <E extends Enum<E>> Class<E> getDeclaringClassOrObjectForJ2cl(E e) {

        a full-time Guava team member. [Feedback](https://stackoverflow.com/a/4543114) from our
        users indicates that they really appreciate Guava's high power-to-weight ratio. It's
        important to us to keep Guava as easy to use and understand as we can. That means boiling
        features down to compact but powerful abstractions, and controlling feature bloat carefully.

        tester.numCallsToVerify,
        tester.numCallsToNewTargetIterator * STEPS);
  }

  public void testVerifyCanThrowAssertionThatFailsTest() {
    final String message = "Important info about why verify failed";
    IteratorTester<Integer> tester =
        new IteratorTester<Integer>(
            1, MODIFIABLE, newArrayList(1, 2, 3), IteratorTester.KnownOrder.KNOWN_ORDER) {
          @Override

   * is.
   *
   * <p>It is recommended that the funnel be implemented as a Java enum. This has the benefit of
   * ensuring proper serialization and deserialization, which is important since {@link #equals}
   * also relies on object identity of funnels.
   *
   * @param funnel the funnel of T's that the constructed {@code BloomFilter} will use

    StringBuilder builder = new StringBuilder();
    Writer writer = new AppendableWriter(builder);

    writer.write("Hello".toCharArray());
    writer.write(',');
    writer.write(0xBEEF0020); // only lower 16 bits are important
    writer.write("Wo");
    writer.write("Whirled".toCharArray(), 3, 2);
    writer.write("Mad! Mad, I say", 2, 2);

    assertEquals("Hello, World!", builder.toString());
  }

import java.math.BigInteger;
import javax.annotation.CheckForNull;

/**
 * A wrapper class for unsigned {@code long} values, supporting arithmetic operations.
 *
 * <p>In some cases, when speed is more important than code readability, it may be faster simply to
 * treat primitive {@code long} values as unsigned, using the methods from {@link UnsignedLongs}.
 *
 * <p>See the Guava User Guide article on <a

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A utility for testing an Iterator implementation by comparing its behavior to that of a "known
 * good" reference implementation. In order to accomplish this, it's important to test a great
 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link
 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>

    assertEquals(safeInput, surrogateEscaper.escape(safeInput));

    // A surrogate pair defining a code point outside the safe range (but both
    // of the surrogate characters lie within the safe range). It is important
    // not to accidentally treat this as a sequence of safe characters.
    String unsafeInput = "\uDBFF\uDFFF"; // 0x10FFFF
    assertEquals("X", surrogateEscaper.escape(unsafeInput));
  }