Method getOnlyElement

guava/src/com/google/common/collect/Iterables.java:261–264

Returns the single element contained in {@code iterable}. <p><b>Java 8+ users:</b> the {@code Stream} equivalent to this method is {@code stream.collect(MoreCollectors.onlyElement())}. @throws NoSuchElementException if the iterable is empty @throws IllegalArgumentException if the iterable contains

(Iterable<T> iterable)

   * @throws IllegalArgumentException if the iterable contains multiple elements
   */
  @ParametricNullness
  public static <T extends @Nullable Object> T getOnlyElement(Iterable<T> iterable) {
    return Iterators.getOnlyElement(iterable.iterator());
  }

  /**
   * Returns the single element contained in {@code iterable}, or {@code defaultValue} if the