throw new NoAvailableChannelException("No healthy channels available");
        }

        if (availableChannels.size() == 1) {
            return availableChannels.iterator().next();
        }

        switch (strategy) {
        case ROUND_ROBIN:
            return selectRoundRobin(availableChannels);

        case LEAST_LOADED:
            return selectLeastLoaded(availableChannels);

    }

    /**
     * Checks if a next page exists.
     *
     * @return true if next page exists, false otherwise
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets the flag indicating if a next page exists.
     *
     * @param existNextPage true if next page exists, false otherwise
     */

        this.existPrePage = existPrePage;
    }

    /**
     * Checks if a next page exists.
     * @return true if a next page exists, false otherwise.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets whether a next page exists.
     * @param existNextPage true if a next page exists, false otherwise.
     */

    }

    /**
     * Checks if there is a next page available.
     *
     * @return true if next page exists, false otherwise
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets whether there is a next page available.
     *
     * @param existNextPage true if next page exists, false otherwise
     */

        this.existPrePage = existPrePage;
    }

    /**
     * Check if the next page exists.
     * @return true if the next page exists.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Set if the next page exists.
     * @param existNextPage true if the next page exists.
     */
    public void setExistNextPage(final boolean existNextPage) {

    }

    /**
     * Checks if there is a next page.
     * @return True if a next page exists, false otherwise.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets the existence of a next page.
     * @param existNextPage True if a next page exists.
     */
    public void setExistNextPage(final boolean existNextPage) {

        this.existPrePage = existPrePage;
    }

    /**
     * Checks if next page exists.
     *
     * @return true if next page exists
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets whether next page exists.
     *
     * @param existNextPage true if next page exists
     */
    public void setExistNextPage(final boolean existNextPage) {

        this.existPrePage = existPrePage;
    }

    /**
     * Checks if a next page exists.
     * @return true if a next page exists, false otherwise.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets whether a next page exists.
     * @param existNextPage true if a next page exists, false otherwise.
     */

    }

    /**
     * Checks if a next page exists.
     *
     * @return true if a next page exists, false otherwise.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets the flag for the existence of a next page.
     *
     * @param existNextPage true if a next page exists.
     */

                return Integer.valueOf(from);
              }
            });

    Iterator<Integer> resultIterator = result.iterator();
    resultIterator.next();

    assertThrows(NumberFormatException.class, () -> resultIterator.next());
  }

  public void testNullFriendlyTransform() {
    List<@Nullable Integer> input = asList(1, 2, null, 3);
    Iterable<String> result =
        Iterables.transform(