<tag>
              <name>implSpec</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>jls</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>revised</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>spec</name>

  `Perhaps it doesn't understand English,' thought Alice; `I
daresay it's a French mouse, come over with William the
Conqueror.'  (For, with all her knowledge of history, Alice had
no very clear notion how long ago anything had happened.)  So she
began again:  `Ou est ma chatte?' which was the first sentence in
her French lesson-book.  The Mouse gave a sudden leap out of the
water, and seemed to quiver all over with fright.  `Oh, I beg

   * QPS=5 (5 tokens per second), if we ensure that a request isn't granted earlier than 200ms after
   * the last one, then we achieve the intended rate. If a request comes and the last request was
   * granted only 100ms ago, then we wait for another 100ms. At this rate, serving 15 fresh permits
   * (i.e. for an acquire(15) request) naturally takes 3 seconds.
   *

            <tag>
              <name>implSpec</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>jls</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>revised</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>spec</name>

-   [Issue tracker: Report a defect or feature request](https://github.com/google/guava/issues/new)
-   [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)
-   [guava-announce: Announcements of releases and upcoming significant changes](https://groups.google.com/group/guava-announce)

 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the
 * resulting XML document is parsed, the parser API will return this text as the original literal
 * string {@code "Foo<Bar>"}.
 *

public abstract class AbstractFuture<V extends @Nullable Object> extends InternalFutureFailureAccess
    implements ListenableFuture<V> {

  static final boolean GENERATE_CANCELLATION_CAUSES = false;

  /**
   * Tag interface marking trusted subclasses. This enables some optimizations. The implementation
   * of this interface must also be an AbstractFuture and must not override or expose for overriding

-   [Issue tracker: Report a defect or feature request](https://github.com/google/guava/issues/new)
-   [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)
-   [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

 * @since 1.0
 */
/*
 * Some of the annotations below were added after we released our separate
 * com.google.guava:listenablefuture:1.0 artifact. (For more on that artifact, see
 * https://github.com/google/guava/releases/tag/v27.0) This means that the copy of ListenableFuture
 * in com.google.guava:guava differs from the "frozen" copy in the listenablefuture artifact. This

 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the
 * resulting XML document is parsed, the parser API will return this text as the original literal
 * string {@code "Foo<Bar>"}.
 *