assertFailsWith<AssertionError> {
      testRule.afterEach(extensionContext)
    }.also { expected ->
      assertThat(expected).hasMessage("uncaught exception thrown during test")
      assertThat(expected.cause!!).hasMessage("boom!")
    }
  }

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Optimization (provides speedup with no functional changes)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Checklist:
- [ ] Fixes a regression (If yes, please add `commit-id` or `PR #` here)
- [ ] Unit tests added/updated
- [ ] Internal documentation updated

 * 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
 * could in principle cause problems for some users. Still, we expect that the benefits of the
 * nullness annotations in particular will outweigh the costs. (And it's worth noting that we have

  /**
   * Invoked when a {@code Future} computation fails or is canceled.
   *
   * <p>If the future's {@link Future#get() get} method throws an {@link ExecutionException}, then
   * the cause is passed to this method. Any other thrown object is passed unaltered.
   */
  void onFailure(Throwable t);

    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    (I hope that this workaround does not cause its own problems in the future.)
-->
<super-source path="super"/>

<inherits name="com.google.gwt.core.Core" />
<inherits name="com.google.gwt.user.User" />

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link SettingsBuilderException}.
     *
     * @return the problems that were encountered during the settings building, can be empty but never {@code null}
     */
    @Nonnull

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link ToolchainsBuilderException}.
     *
     * @return the problems that were encountered during the settings building, can be empty but never {@code null}
     */
    @Nonnull

            CollectionSize.ANY)
        .withSetUp(setUp)
        .withTearDown(tearDown)
        .createTestSuite();
  }

  private static LinkageError newLinkageError(Throwable cause) {
    return new LinkageError(cause.toString(), cause);
  }

   *
   * @param exceptionType the exception type that triggers use of {@code fallback}. The exception
   *     type is matched against this step's exception. "This step's exception" means the cause of
   *     the {@link ExecutionException} thrown by {@link Future#get()} on the {@link Future}
   *     underlying this step or, if {@code get()} throws a different kind of exception, that

      return this;
    }

    /**
     * Associates the ({@code rowKey}, {@code columnKey}) pair with {@code value} in the built
     * table. Duplicate key pairs are not allowed and will cause {@link #build} to fail.
     */
    @CanIgnoreReturnValue
    public Builder<R, C, V> put(R rowKey, C columnKey, V value) {
      cells.add(cellOf(rowKey, columnKey, value));
      return this;
    }