How to contribute
=================

Thank you so much for wanting to contribute to Guava! Here are a few important
things you should know about contributing:

1.  API changes require discussion, use cases, etc. Code comes later.
2.  Pull requests are great for small fixes for bugs, documentation, etc.
3.  Pull requests are not merged directly into the master branch.
4.  Code contributions require signing a Google CLA.

API changes
-----------

        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.

  - type: textarea
    attributes:

-   [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

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));
  }

       * timeoutFuture.setException() calls run(). That reentrancy would already be harmless, since
       * timeoutFuture can be set (and delegate cancelled) only once. (And "set only once" is
       * important for other reasons: run() can still be invoked concurrently in different threads,
       * even with the above null checks.)
       */
      timeoutFutureRef = null;
      if (delegate.isDone()) {

import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link RangeMap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * @author Louis Wasserman
 * @since 14.0
 */
@GwtIncompatible // NavigableMap
@ElementTypesAreNonnullByDefault

   * 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.

-   [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