<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>

            <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-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

-   [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)

 * @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

    } catch (SecurityException e) {
      generateCancellationCauses = false;
    }
    GENERATE_CANCELLATION_CAUSES = generateCancellationCauses;
  }

  /**
   * 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

 *
 * <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

 * @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>"}.
 *