assertThrows(IllegalStateException.class, () -> emptyAccumulator.sampleVariance());
    assertThrows(
        IllegalStateException.class, () -> emptyAccumulatorByAddAllEmptyIterable.sampleVariance());
    assertThrows(
        IllegalStateException.class, () -> emptyAccumulatorByAddAllEmptyStats.sampleVariance());
    assertThrows(IllegalStateException.class, () -> oneValueAccumulator.sampleVariance());
    assertThrows(

  }

  public void testGap_invalidRangesWithInfinity() {
    assertThrows(IllegalArgumentException.class, () -> Range.atLeast(1).gap(Range.atLeast(2)));

    assertThrows(IllegalArgumentException.class, () -> Range.atLeast(2).gap(Range.atLeast(1)));

    assertThrows(IllegalArgumentException.class, () -> Range.atMost(1).gap(Range.atMost(2)));

    }

    private static class DocCommentImpl implements DocComment {
        private final List<Element> nodes;

        public DocCommentImpl(List<Element> nodes) {
            this.nodes = nodes;
        }

        @Override
        public List<Element> getDocbook() {
            return nodes;
        }
    }

    }

    @Override
    protected Class<? extends ClickLog> typeOfSelectedEntity() {
        return ClickLog.class;
    }

    @Override
    protected Class<ClickLog> typeOfHandlingEntity() {
        return ClickLog.class;
    }

    @Override
    protected Class<ClickLogCB> typeOfHandlingConditionBean() {
        return ClickLogCB.class;
    }

    }

    @Override
    protected Class<? extends Group> typeOfSelectedEntity() {
        return Group.class;
    }

    @Override
    protected Class<Group> typeOfHandlingEntity() {
        return Group.class;
    }

    @Override
    protected Class<GroupCB> typeOfHandlingConditionBean() {
        return GroupCB.class;
    }

    }

    @Override
    protected Class<? extends AccessToken> typeOfSelectedEntity() {
        return AccessToken.class;
    }

    @Override
    protected Class<AccessToken> typeOfHandlingEntity() {
        return AccessToken.class;
    }

    @Override
    protected Class<AccessTokenCB> typeOfHandlingConditionBean() {
        return AccessTokenCB.class;
    }

    }

    @Override
    protected Class<? extends DuplicateHost> typeOfSelectedEntity() {
        return DuplicateHost.class;
    }

    @Override
    protected Class<DuplicateHost> typeOfHandlingEntity() {
        return DuplicateHost.class;
    }

    @Override
    protected Class<DuplicateHostCB> typeOfHandlingConditionBean() {
        return DuplicateHostCB.class;
    }

    }

    @Override
    protected Class<? extends ElevateWord> typeOfSelectedEntity() {
        return ElevateWord.class;
    }

    @Override
    protected Class<ElevateWord> typeOfHandlingEntity() {
        return ElevateWord.class;
    }

    @Override
    protected Class<ElevateWordCB> typeOfHandlingConditionBean() {
        return ElevateWordCB.class;
    }

    }

    @Override
    protected Class<? extends KeyMatch> typeOfSelectedEntity() {
        return KeyMatch.class;
    }

    @Override
    protected Class<KeyMatch> typeOfHandlingEntity() {
        return KeyMatch.class;
    }

    @Override
    protected Class<KeyMatchCB> typeOfHandlingConditionBean() {
        return KeyMatchCB.class;
    }

    }

    @Override
    protected Class<? extends RequestHeader> typeOfSelectedEntity() {
        return RequestHeader.class;
    }

    @Override
    protected Class<RequestHeader> typeOfHandlingEntity() {
        return RequestHeader.class;
    }

    @Override
    protected Class<RequestHeaderCB> typeOfHandlingConditionBean() {
        return RequestHeaderCB.class;
    }