Method left

core/src/main/java/org/apache/calcite/util/Pair.java:341–344

Returns an iterable over the left slice of an iterable. @param iterable Iterable over pairs @param Left type @param Right type @return Iterable over the left elements

(
      final Iterable<? extends Map.Entry<? extends L, ? extends R>> iterable)

   * @return Iterable over the left elements
   */
  public static <L, R> Iterable<L> left(
      final Iterable<? extends Map.Entry<? extends L, ? extends R>> iterable) {
    return Util.transform(iterable, Map.Entry::getKey);
  }

  /**
   * Returns an iterable over the right slice of an iterable.