} finally {
            deleteScrollContext(scrollId);
        }
    }

    protected void deleteScrollContext(final String scrollId) {
        if (scrollId != null) {
            client.prepareClearScroll().addScrollId(scrollId).execute(ActionListener.wrap(() -> {}));
        }
    }

    @Override
    protected Number doReadNextVal() {

        } finally {
            deleteScrollContext(scrollId);
        }
    }

    protected void deleteScrollContext(final String scrollId) {
        if (scrollId != null) {
            client.prepareClearScroll().addScrollId(scrollId).execute(ActionListener.wrap(() -> {}));
        }
    }

    @Override
    protected Number doReadNextVal() {

        } finally {
            deleteScrollContext(scrollId);
        }
    }

    protected void deleteScrollContext(final String scrollId) {
        if (scrollId != null) {
            client.prepareClearScroll().addScrollId(scrollId).execute(ActionListener.wrap(() -> {}));
        }
    }

    @Override
    protected Number doReadNextVal() {